116 results on '"Hamad A. Al-Lohedan"'
Search Results
2. Star fruit extract-mediated green synthesis of metal oxide nanoparticles
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Selvaraj Vennila, Mohd Rafie Johan, Faruq Mohammad, J. Anita Lett, Solhe F. Alshahateet, M. A. Motalib Hossain, Is Fatimah, Sagadevan Suresh, and Hamad A. Al-Lohedan
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Chemistry ,02 engineering and technology ,Metal oxide nanoparticles ,Star (graph theory) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Star fruit extract ,Physical and Theoretical Chemistry ,0210 nano-technology ,Antibacterial activity ,human activities ,Nuclear chemistry - Abstract
The present study deals with the green synthesis, physical characterization, and antibacterial activity testing of various metal oxide nanoparticles (NPs) formed by making use of the star fruit ext...
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- 2021
3. Polymer surfactant (Triton-100) assisted low cost method for preparing silver and graphene oxide modified Bi-MnOx nanocomposite for enhanced sensor and anti-microbial health care applications
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Wasmiah Mohammed Dahan, Prabhakarn Arunachalam, Thiruchelvi Pulingam, Radhika Thankappan, Jimmy Nelson Appaturi, Hamad A. Al-Lohedan, and Jothi Ramalingam Rajabathar
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Nanotube ,Materials science ,Oxide ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Silver nanoparticle ,law.invention ,Biomaterials ,chemistry.chemical_compound ,law ,Materials Chemistry ,Nanocomposite ,Graphene ,technology, industry, and agriculture ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,chemistry ,Ceramics and Composites ,Particle ,Particle size ,0210 nano-technology - Abstract
Silver nanoparticles decorated on nanotubes morphology of Bismuth doped manganese oxide (Bi-MnOx) was prepared by Triton-X-100 polymer assisted precipitation process. In the second step, Ag nanoparticle with very fine particle size and graphene nanoparticle deposition by high power ultra-sonication method. Biogenic route synthesized silver nanoparticles have forms the spherical particle morphology with particle size obtained
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- 2021
4. Facile fabrication of Au-loaded CdO nanoconstructs with tuned properties for photocatalytic and biomedical applications
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Solhe F. Alshahateet, Suresh Sagadevan, Hamad A. Al-Lohedan, J. Anita Lett, Is Fatimah, Baranya Murugan, Faruq Mohammad, Lakshmipathy Muthukrishnan, Selvaraj Vennila, and M. A. Motalib Hossain
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Materials science ,Nanoparticle ,Nanochemistry ,Context (language use) ,02 engineering and technology ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Coating ,Chemical engineering ,Cadmium oxide ,Rhodamine B ,engineering ,Photocatalysis ,Fourier transform infrared spectroscopy ,0210 nano-technology - Abstract
Cadmium oxide (CdO) had long been investigated for decades as prototypical wide-band-gap transparent conducting oxides (TCOs) possessing excellent n-type ability having its implications in the field of photo electronics. Despite this, there exists an uncertainty on the toxicity of CdO content during the synthesis and product retrieval which limits their use in biological applications. In this context, an approach to enhance the inbuilt properties of CdO particles by the means of loading (in coating form) with gold (Au) nanoparticles (NPs) to generate Au@CdO nanoconstructs (NCs) has been reported. Thus, formed Au@CdO NCs have been characterized by various spectroscopic and electron microscopic analysis for the structural, optical, and biological properties. For example, the UV–Vis spectroscopy revealed a typical λmax of CdO at 302 nm, and for the Au@CdO, a shift toward 496 nm was observed. The diffraction pattern demonstrated the crystalline phase corresponding to (1 1 1) plane with mean grain sizes of 24.9 and 30.6 nm for the CdO and Au@CdO, respectively. The FTIR and optical studies highlighted the intermolecular bonding with an increased bandgap confirming the efficient coating of Au onto CdO. The FESEM demonstrated spherical-to-elliptical-shaped anisotropic particles following the coating of CdO with Au and the grain size getting increased from 30 to 42 nm. On testing of the photocatalytic activity, we found that the Au@CdO NCs efficiently degraded the Rhodamine B dye (96% in 180 min) following the irradiation under artificial UV light. Furthermore, the Au@CdO NCs showed a significant antimicrobial effect at 80 μg/mL associated with a decline in the cell count. Alongside, the IC50 of Au@CdO against A549 and PBMC cells was fixed at 46.87 and 55.14 μg/mL, respectively. Such multifaceted Au@CdO NCs possessing optical properties might present themselves as the potential candidates for the extended photocatalytic and biomedical applications.
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- 2021
5. Exploration of the antibacterial capacity and ethanol sensing ability of Cu-TiO2 nanoparticles
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Suresh Sagadevan, Muhammad Mehmood Shahid, Suriati Paiman, Is Fatimah, Prasanna Kumar Obulapuram, Hamad A. Al-Lohedan, Preeti Singh, Won-Chun Oh, Faruq Mohammad, J. Anita Lett, and Selvaraj Vennila
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staphylococcus aureus ,Materials science ,ethanol detection ,Biomedical Engineering ,cu-doped tio2 ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,medicine.disease_cause ,lcsh:Chemical technology ,01 natural sciences ,chemistry.chemical_compound ,antibacterial activity ,medicine ,lcsh:TA401-492 ,General Materials Science ,lcsh:TP1-1185 ,Escherichia coli ,Ethanol ,Tio2 nanoparticles ,chemical sensors ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Titanium oxide ,chemistry ,Staphylococcus aureus ,phase transition ,lcsh:Materials of engineering and construction. Mechanics of materials ,escherichia coli ,0210 nano-technology ,Antibacterial activity ,Nuclear chemistry - Abstract
Titanium oxide (TiO2) is one of the most scrutinized material because of its in-built fundamental properties and has been developed as an outstanding photo-catalytic material intended for many different industrial applications. In order to further explore the properties of TiO2, we prepared Copper-loaded TiO2 (Cu-TiO2) nanoparticles (NPs) for inhibiting the growth of bacterial cells and also to serve as a chemical sensor. The physico-chemical characteristics of the synthesized Cu-TiO2 NPs were characterized by many different techniques for the crystallinity, bonding and functionality, morphology, elemental composition, and absorption characteristics. From the results, we confirm for the formation of anatase phase of TiO2 having a tetragonal crystal system, while the morphology studies indicated that the Cu dope TiO2 has spherical morphology. The elemental analysis confirmed for the inclusion of Cu into TiO2 crystal lattice and the absorption spectroscopic analysis helped for the bandgap calculation and visible light absorption property of Cu-TiO2 NPs. The metal nanoclusters of Cu are observed to be deposited on different phases and sites of TiO2 resulting in the inter-band transitions. Further, the sensitivity of Cu-TiO2 as a chemical sensor is determined by fabricating the electrode at the FTO glass substrate where the ethanol sensitivity was found to be little increased/enhanced with Cu loading. Finally, the antibacterial activity of Cu-TiO2 NPs was confirmed by its activity against various bacterial cultures and are found to be efficient.
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- 2020
6. Exploring the therapeutic potentials of phyto-mediated silver nanoparticles formed via Calotropis procera (Ait.) R. Br. root extract
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Suriati Paiman, K. Gurunathan, Hamad A. Al-Lohedan, Suresh Sagadevan, Lakshmipathy Muthukrishnan, Won-Chun Oh, Is Fatimah, Ainil Hawa Jasni, Selvaraj Vennila, K. Sivaranjan, Faruq Mohammad, and Prasanna Kumar Obulapuram
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Green chemistry ,silver nanoparticles ,Materials science ,Biomedical Engineering ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,lcsh:Chemical technology ,01 natural sciences ,antimicrobial assay ,Silver nanoparticle ,Calotropis procera ,lcsh:TA401-492 ,General Materials Science ,lcsh:TP1-1185 ,Metal nanoparticles ,biology ,green synthesis ,021001 nanoscience & nanotechnology ,biology.organism_classification ,0104 chemical sciences ,Antimicrobial assay ,plant extract ,cytotoxicity ,lcsh:Materials of engineering and construction. Mechanics of materials ,0210 nano-technology ,calotropis procera ,Nuclear chemistry - Abstract
The objective of this work is to develop cost-effective, reliable, and large-scale production of metallic nanoparticles (NPs) by adopting green chemistry principles for industrial applications. In that view, we have studied the phytochemical reducibility of silver nitrate by making use of Calotropis Procera (Ait.) R. Br root extract, and based on its medicinal properties, an attempt was made to evaluate the therapeutic potentials of silver (Ag) NPs containing this plant extract towards the clinical strains of bacteria. The optimization studies on reducing the potentials were done considering the concentration, pH, temperature, and reaction period of both the extract and the metal precursor. The nanoarchitecture elements were interpreted using visual, spectroscopic, and microscopic analyses cohorting the antibacterial potentials towards the clinically significant strains. The antimicrobial activity exercised by these Ag NPs towards 10 different strains of medically important bacteria at a given concentration was proved to be significant. The antimicrobial potential was further validated quantitatively, and the MIC/MBC concentration values were determined. Finally, the cytotoxicity of Ag NPs when tested against the HEPK cell line indicated that the metal-phytochemical moiety exhibited the maximum therapeutic efficacy and thereby paving the way for the development of disruptive technologies in the field of nanomedicine.
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- 2020
7. Review on Carbon Dioxide Utilization for Cycloaddition of Epoxides by Ionic Liquid-Modified Hybrid Catalysts: Effect of Influential Parameters and Mechanisms Insight
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Muthu Kumaran Gnanamani, Farook Adam, Prabhakarn Arunachalam, Rajabathar Jothi Ramalingam, Hamad A. Al-Lohedan, Jimmy Nelson Appaturi, Mohammed D. Wasmiah, Govindasami Periyasami, and Rohana Adnan
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Ionic bonding ,02 engineering and technology ,010402 general chemistry ,lcsh:Chemical technology ,01 natural sciences ,Catalysis ,lcsh:Chemistry ,chemistry.chemical_compound ,Styrene oxide ,lcsh:TP1-1185 ,mesoporous silica ,Physical and Theoretical Chemistry ,cycloaddition ,ionic liquid ,Chemistry ,021001 nanoscience & nanotechnology ,Cycloaddition ,0104 chemical sciences ,Chemical engineering ,lcsh:QD1-999 ,greenhouse gas ,Ionic liquid ,Carbonate ,poly-carbonate ,Solvent effects ,0210 nano-technology ,Mesoporous material - Abstract
The storage, utilization, and control of the greenhouse (CO2) gas is a topic of interest for researchers in academia and society. The present review article is dedicating to cover the overall role of ionic liquid-modified hybrid materials in cycloaddition reactions. Special emphasis is on the synthesis of various cyclic carbonate using ionic liquid-based modified catalysts. Catalytic activity studies have discussed with respect to process conditions and their effects on conversion and product selectivity for the reaction of cycloaddition of CO2 with styrene oxide. The reaction temperature and the partial pressure of CO2 have found to play a key role in cyclic carbonate formation. The role of other influential parameter (solvent effect) is also discussed for the conversion of cyclic/aromatic oxides to polycarbonate production. Our own research work that deals with ionic liquid-based halide-modified mesoporous catalyst (MCM-41 type) derived from rice husk waste has also been discussed. Finally, the role of carbon dioxide activation and ring-opening mechanisms involved in the cyclic carbonate product formation from CO2 have been discussed.
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- 2021
8. Characterization and optimization of influence of MoS2 hybridization on tribological behaviours of Mg–B4C composites
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Hamad A. Al-Lohedan, P. R. Rajkumar, Sikiru Oluwarotimi Ismail, C. Kailasanathan, T Ramesh, Faruq Mohammad, G D Sivakumar, and Nagarajan Rajini
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Thermogravimetric analysis ,Materials science ,Scanning electron microscope ,Delamination ,Composite number ,02 engineering and technology ,Tribology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Carbide ,Corrosion ,Mechanics of Materials ,Powder metallurgy ,General Materials Science ,Composite material ,0210 nano-technology - Abstract
Aerospace and automobile industries are facing challenges in developing lightweight materials with high corrosion and wear resistance. The magnesium (Mg) alloys are superior to their monolithics, as they have maximum strength-to-weight ratio. These challenges can be solved with application of Mg-based hybrid composites. Therefore, this study investigated the hybridizing effect of molybdenum disulphide (MoS2) reinforcement on tribological performance of magnesium–boron carbide (Mg–B4C) hybrid composites, fabricated by powder metallurgy technique. Wear tests under dry sliding condition were carried out on the prepared composite samples with different proportions/weight percentage (wt%), using a pin-on-disc apparatus. Mg, MoS2, B4C and their various composites were characterized, using X-ray diffraction, thermogravimetric analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analysis. The experiments were conducted using L27 orthogonal array with five factors at three levels that affected the tribological performance. The wear resistance of the hybrid Mg–B4C–MoS2 composites significantly increased when compared with Mg–B4C and Mg–MoS2 composites, due to the refined effect of both reinforcements. Analysis of variance and grey-relational analysis result showed that increase in MoS2, sliding distance (DSl) and load (LSl) significantly influenced the tribological performance of the hybrid composites. Mg–10wt%B4C–5wt%MoS2 exhibited significant best improvement on the multi-response tribological performance. The optimum quantity of MoS2 reinforcement was around 7 wt%. Beyond this threshold proportion, wear was significantly increased, due to the agglomeration of MoS2 particles. Hardness of the composites increased with hybridized reinforcements. SEM micrographs depicted the homogeneous dispersion of reinforcements in the Mg matrix. Also, SEM micrographs of the worn surfaces confirmed that delamination wear mechanism was dominant on the Mg hybrid composites.
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- 2021
9. Platinum nanoparticle decorated rutile titania synthesized by surfactant free hydrothermal method for visible light catalysis for dye degradation and hydrogen production study
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R. Jothi Ramalingam, P. Reshma Ranjan, Hamad A. Al-Lohedan, Shaban R.M. Sayed, T. Radhika, A. Meera Moydeen, and Dhaifallah Al-Dhayan
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Materials science ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Platinum nanoparticles ,01 natural sciences ,Hydrothermal circulation ,0104 chemical sciences ,Catalysis ,Titanium oxide ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Chemical engineering ,Rutile ,Methanol ,0210 nano-technology ,Platinum ,Hydrogen production - Abstract
Rutile phase of titanium oxide and platinum nanoparticle decorated rutile titania is prepared by a surfactant free hydrothermal process in acidic condition. The pure rutile phase of TiO2 particle is forms the specific cauliflower morphology. Hydrothermal process in presence of specific acid addition led to the formation of cauli-flower shaped rutile phase of titania. The efficiency and solar assisted photo catalytic ability of these materials are tested for methylene blue degradation as well as hydrogen generation by methanol reforming process. The X-ray diffraction of pattern of pure rutile phase formation is confirmed by reported JCPDS data. The surface physico-chemical property of prepared rutile Titania is further characterized by BET, Raman and SEM analysis. The HR-TEM of the prepared samples show the reduced particle size for rutile titania and studied their morphology in detail. Solar light assisted methylene blue degradation reaction was carrying out to study the catalytic efficiency towards dye degradation and kinetic activity of the same for prepared commercial titania and pure rutile TiO2. The platinum loaded and photo deposited rutile Titania is further analyzed for hydrogen production reaction by methanol reforming process. The rate of hydrogen evolution on platinum nanoparticle photo deposited on reforming process shows more than 900 μmol/g compared to pristine rutile titania catalysts.
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- 2019
10. Ultrasound-assisted synthesis of tungsten trioxide entrapped with graphene nanosheets for developing nanomolar electrochemical (hormone) sensor and enhanced sensitivity of the catalytic performance
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Hamad A. Al-Lohedan, Sea-Fue Wang, R. Jothi Ramalingam, Bowya Subramanian, Sathishkumar Chinnapaiyan, and Mani Govindasamy
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Materials science ,Acoustics and Ultrasonics ,Surface Properties ,Nanotechnology ,Chemistry Techniques, Synthetic ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysis ,Tungsten ,law.invention ,Inorganic Chemistry ,chemistry.chemical_compound ,Limit of Detection ,law ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Environmental Chemistry ,Radiology, Nuclear Medicine and imaging ,High-resolution transmission electron microscopy ,Electrodes ,Detection limit ,Nanocomposite ,Graphene ,Organic Chemistry ,Temperature ,Oxides ,021001 nanoscience & nanotechnology ,Tungsten trioxide ,Amperometry ,0104 chemical sciences ,Ultrasonic Waves ,chemistry ,Electrode ,Graphite ,0210 nano-technology ,Oxidation-Reduction ,Biosensor - Abstract
Herein, we have reported a simple sonochemical synthesis of multi-layer graphene covered tungsten trioxide nanoballs (WO3 NBs) and the nanocomposite was characterized by FESEM, HRTEM, XRD, XPS, CV and EIS. Furthermore, progesterone (PGT) is a preferred marker for various biological problems like pregnancy problem, mood swings, anxiety, depression, nervousness and body pain. Therefore, its selective and sensitive determination in various biological fluids is beneficial for the evaluation of malformation problems. We describe the fabrication of an amperometric and non-enzymatic biosensor based on WO3 NBs@GR nanocomposite modified electrode for nanomolar detection of PGT. The results showed that the nanocomposite modified electrode exhibit well-defined electro-oxidation peak compared to bare and control electrodes, demonstrating the superior electrocatalytic ability and performances. The fabricated modified sensor was facilitates the analysis of PGT in the concentration ranges of 0.025–1792.5 µM with a low detection limit of 4.28 nM. Further, the as-prepared WO3 NBs@GR electrode has been applied to determination of PGT in human blood samples with outstanding recovery results and more importantly, the facile and environment-friendly sonochemical construction strategy extended here, may be open a cost-effective way for setting up the nanocomposites based (bio) sensing platform.
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- 2019
11. Biocompatible polylactic acid-reinforced nickel–arsenate composite: Studies of electrochemical conductivity, mechanical stability, and cell viability
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Tanvir Arfin, Faruq Mohammad, and Hamad A. Al-Lohedan
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Time Factors ,Materials science ,Cell Survival ,Polyesters ,Composite number ,Biocompatible Materials ,Bioengineering ,02 engineering and technology ,Conductivity ,010402 general chemistry ,01 natural sciences ,Cell Line ,Biomaterials ,chemistry.chemical_compound ,Polylactic acid ,Flexural strength ,Nickel ,Electrical resistivity and conductivity ,Elastic Modulus ,Tensile Strength ,Spectroscopy, Fourier Transform Infrared ,Ultimate tensile strength ,Animals ,Composite material ,Cell Proliferation ,chemistry.chemical_classification ,Nanocomposite ,Electric Conductivity ,Polymer ,021001 nanoscience & nanotechnology ,Rats ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,Arsenates ,0210 nano-technology ,Porosity - Abstract
In continuation to our earlier work on nickel (Ni)-arsenate (As) composite, the current work deals with the electrical conductivity and mechanical resistivity of the same composite by means of its further reinforcement with the polylactic acid (PLA) polymer. For the PLA-Ni-As composite, we understand from the electrochemical studies that the conductivity is strongly influenced by the temperature and due to the presence of external electrolyte. The DC electrical conductivity approach used for the temperature dependency provided the information that the conductivity falls in the semiconductor zone ranging at 10−3 S cm−1, thereby indicating that it followed the Arrhenius equation. In addition, we found in terms of the mechanical properties that the PLA-Ni-As composite outperformed the plain, untreated Ni-As composite by reducing the activation energy. For the mechanical resistivity studies we found that the 25% PLA-loaded Ni-As material significantly improved the tensile strength and modulus, elongation at break %, impact properties and also the flexural strength and modulus as against the plain and other combinations due to enhanced interfacial interactions. The cell viability and proliferations studies tested against two different cell lines provided the information that the presence of polymer reduces the toxic response of arsenic material. From the cumulative analysis therefore, we indicate that the PLA-Ni-As composite can be a potential candidate to find its uses in the electrochemical and solar cells, in addition to automotive and aerospace industry.
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- 2019
12. Synthesis, characterization and catalytic activity of ionic liquid mimic halides modified MCM-41 for solvent free synthesis of phenyl glycidyl carbonate
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Thiruchelvi Pulingam, Noora Ibrahim S, Hamad A. Al-Lohedan, R. Jothi Ramalingam, and Jimmy Nelson Appaturi
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Chemistry ,Halide ,02 engineering and technology ,Mesoporous silica ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Cycloaddition ,0104 chemical sciences ,Catalysis ,Hexane ,chemistry.chemical_compound ,MCM-41 ,Ionic liquid ,Polymer chemistry ,General Materials Science ,0210 nano-technology ,Selectivity - Abstract
The different type of halide modified mesoporous silica catalysts were prepared via post-grafting technique using meso-silica derived from rich husk by simple sol-gel method. The physico chemical characterizations of as prepared catalysts were characterized using FT-IR, N2-sorption-desorption study, 13C CP/MAS NMR and SEM techniques. FT-IR and 13C CP/MAS NMR revealed the effective anchorage of imidazole and 1,2-dihaloethane on the MCM-41. SEM analysis images shows the comprise worm-like agglomerated structure which was similar to MCM-41. The catalysts were then used in cycloaddition of carbon dioxide and phenyl glycidyl ether under solvent free or less conditions. Among the prepared catalyst, Br-immobilized MCM-41 shows higher catalytic activity (96.7%) under ambient reaction by adopting following conditions such as 100 °C, 20 bar initial CO2 pressure, 300 mg catalyst mass and 3 h. The conversion of phenyl glycidyl ether using ImI-MCM-41 and ImCl-MCM-41 are 77.3% and 26.4% respectively. The catalytic results are confirmed that the synergistic effect owing to the stronger nucleophilicity of bromide− and amine could be promoted the reaction smoothly. The catalyst was recovered and reused for four times without a significant decrease in activity or product selectivity. A possible site for CO2 activation by ImBr-MCM-41 catalyst could be the potential ionic liquid mimic's halide immobilized MCM-41 like material for efficient conversion of the substrates such as phenyl glycidyl ether and Epoxy hexane for cycloaddition reactions have been demonstrated.
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- 2019
13. Enhanced biosorption and electrochemical performance of sugarcane bagasse derived a polylactic acid-graphene oxide-CeO2 composite
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Tanvir Arfin, Hamad A. Al-Lohedan, and Faruq Mohammad
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chemistry.chemical_classification ,Materials science ,Composite number ,technology, industry, and agriculture ,Biosorption ,Langmuir adsorption model ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,symbols.namesake ,Adsorption ,Polylactic acid ,chemistry ,Chemical engineering ,Desorption ,symbols ,Methyl orange ,General Materials Science ,0210 nano-technology - Abstract
In view of the methyl orange (MO) dye on everyday applications in the textile, food, leather, paper, printing, and pharmaceuticals industry, in addition to its toxic behaviour on human health, we have developed a biodegradable polylactic acid (PLA)-based cerium dioxide (CeO2)-graphene oxide (GO) composite by means of a sol-gel technique and tested its efficacy. For the study, the PLA polymer obtained is of renewable agriculture waste origin (sugarcane bagasse) and was isolated by means of fermentation of the feedstock followed by the polymerization of lactic acid. The instrumental techniques such as the powdered x-ray diffraction, scanning electron microscopy etc. were employed for the physical characterization of the material. The various parameters such as the kinetics, desorption, regeneration, pH, isotherm theories, and ionic strength were tested towards the adsorption of MO dye onto the surface of GO-PLA-CeO2 composite. The outcome of the study exhibited that the GO-PLA-CeO2 composite revealed promising behaviour for the dye removal, which was allocated to the efficacy of GO, PLA, and CeO2 properties. Also, the adsorption process of GO-PLA-CeO2 is completely dependent on the initial concentration of MO and the adsorption equilibrium fitted well with the Langmuir isotherm. In addition, the electrochemical characterization of the composite was studied by means of CV and impedance measurements. Based on the outcome of the results, it can be said that the GO-PLA-CeO2 composite may be applied as a suitable electrode material along with its efficient adsorption properties for the removal of MO dye from wastewater.
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- 2019
14. New hydrophobic silica nanoparticles capped with petroleum paraffin wax embedded in epoxy networks as multifunctional steel epoxy coatings
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Ayman M. Atta, Hamad A. Al-Lohedan, Nermen H. Mohamed, Mahmood M. S. Abdullah, and Merit Rostom
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Materials science ,General Chemical Engineering ,Organic Chemistry ,Nanoparticle ,02 engineering and technology ,Epoxy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Silane ,0104 chemical sciences ,Surfaces, Coatings and Films ,Contact angle ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Paraffin wax ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Thermal stability ,Wetting ,0210 nano-technology ,Hydrophobic silica - Abstract
The silane amide precursors were prepared by amidation of oleic and stearic acid with γ-aminopropyltriethoxysilane. The stearyl and oleyl amines were added to vinyl trimethoxy silane to synthesize aminosilane precursors. The chemical structures, surface morphology, thermal stability of the prepared hydrophobic silica nanoparticles were investigated. The wetting characteristics, mechanical properties, thermal stability and corrosion resistance of the prepared hydrophobic silica nanoparticles with epoxy composites coated on the steel panels were studied. The data confirm that the all the prepared hydrophobic silica show higher contact angles (100-110°) when blended with epoxy up to 3Wt %. Moreover, the dispersion, hydrophobicity and paraffin wax contents of silica nanoparticles embedded into epoxy networks control the high corrosion resistivity of the composites as organic coatings of steel substrate. The salt spray resistance data elucidate that the epoxy modified with 1 Wt % of the hydrophobic silica/paraffin wax achieved higher salt spray resistances up to 1500 h with high rating.
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- 2019
15. Experimental and computational investigation on the molecular interactions of safranal with bovine serum albumin: Binding and anti-amyloidogenic efficacy of ligand
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Mohd. Sajid Ali and Hamad A. Al-Lohedan
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02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Hydrophobic effect ,chemistry.chemical_compound ,Materials Chemistry ,Physical and Theoretical Chemistry ,Bovine serum albumin ,Protein secondary structure ,Spectroscopy ,chemistry.chemical_classification ,Quenching (fluorescence) ,biology ,Chemistry ,Hydrogen bond ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Ligand (biochemistry) ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Safranal ,Amino acid ,biology.protein ,Biophysics ,0210 nano-technology - Abstract
Molecular interaction between BSA and safranal was seen in the present study using experimental and molecular docking methods, in addition, inhibitory effect of safranal towards BSA amyloid formation was also seen. UV–visible and fluorescence studies suggested the formation of 1:1 complex between BSA and safranal via static quenching mechanism. The corrected fluorescence spectra showed a blue shift in the emission maximum on the successive addition of safranal which revealed the involvement of hydrophobic forces in the interaction. Far-UV CD measurements suggested the stabilization of secondary structure of BSA by increasing its α-helical contents, i.e., compaction of protein and that was further supported by RLS and DLS methods. Analysis of thermodynamic parameters presented that hydrophobic forces as well as hydrogen bonding were involved in the binding. From the competitive assay and molecular docking simulations it was found that safranal binds near the Sudlow's site 1 in the subdomain IIA and most of the amino acids residues bound with hydrophobic forces and a few with hydrogen bonding. Safranal was found to inhibit the BSA amyloid formation and the inhibition was concentration dependent. Exposed surface hydrophobicity of BSA amyloid fibrils was decreased considerably in presence of safranal.
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- 2019
16. Fluorescent delivery vehicle containing cobalt oxide–umbelliferone nanoconjugate: DNA/protein interaction studies and anticancer activity on MF7 cancer cell line
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Mohammad Usman, Khalid Mashay Al-Anazi, Hamad A. Al-Lohedan, Mohammad Abul Farah, Sartaj Tabassum, and Mohd. Sajid Ali
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chemistry.chemical_classification ,General Chemical Engineering ,Biomolecule ,Sonication ,Metal ions in aqueous solution ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Umbelliferone ,01 natural sciences ,Fluorescence ,Combinatorial chemistry ,0104 chemical sciences ,Nanomaterials ,chemistry.chemical_compound ,chemistry ,0210 nano-technology ,Drug carrier ,Conjugate - Abstract
Fluorescent labeling is limited to certain molecules and alters biomolecule functionality. A new class of nanomaterial with anticancer activity and fluorescence properties has been designed and prepared. This nanotherapeutic conjugate of natural molecules has a selective binding site in cancer cell lines. Natural drug umbelliferone was taken with cobalt metal ions in a one pot assembly in the presence of tannic acid which yields new fluorescent nanoparticles of umbelliferone cobalt oxide nanoconjugate. Umbelliferone has high fluorescent properties and also has coordination ability to bind with central metal ions. The nanoconjugate was synthesized and characterized by using TEM, EDX analysis, SEM, XRD, and FTIR spectroscopy. TEM shows that the average size of the particles formed with umbelliferone is ∼20 nm. The solubility of the drug nanoparticles in water showed compatibility with cancer cells and provided a favorable environment to investigate the mechanism of action on the MCF-7 cell line. The nanoconjugate is microcrystalline in nature and gives a clear suspension in water. The nanocobalt conjugate was loaded on TiO2 nanoparticles by ultrasonication, and the solution was digested overnight. The conjugate of the drug with a TiO2 drug carrier was stable in solution and maintained the nanostructure ∼34.6 nm. A comparative study with nano-vehicle TiO2 and the nanoconjugate was performed. TiO2 was used to compare the anti-cancer activity of the nanoconjugate at low dose in vitro. It was observed that the nanoconjugate with TiO2 is capable of reaching the specific target like the TiO2 nanoparticle and enhance the chemotherapeutic impact. Hence, the nanoconjugate can also be used like nano-TiO2, as the drug and carrier. The ct-DNA and HSA protein binding studies were done and validated by docking studies.
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- 2019
17. Silver-embedded epoxy nanocomposites as organic coatings for steel
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Ashraf M. El-Saeed, Zeid A. Al Othman, Ayman El-Faham, Abdelrahman O. Ezzat, Ayman M. Atta, Sameh M. Osman, and Hamad A. Al-Lohedan
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Thermogravimetric analysis ,Materials science ,Scanning electron microscope ,General Chemical Engineering ,Organic Chemistry ,Composite number ,02 engineering and technology ,Epoxy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Silver nanoparticle ,0104 chemical sciences ,Surfaces, Coatings and Films ,Nanomaterials ,Chemical engineering ,visual_art ,Materials Chemistry ,Zeta potential ,visual_art.visual_art_medium ,0210 nano-technology ,Hybrid material - Abstract
A novel hybrid nanomaterial based on silver nanoparticles, AgNPs, supported by 2,4-dihydrazino-6-(methoxypolyethyleneglycol)-1,3,5-triazine (mPEGTH) was prepared using solid phase technique. The synthesis process and the structural properties of the AgNPs were analyzed through X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmittance and scanning electron microscopy (TEM and SEM). The effect of seawater, and pH of solutions on the aggregation and zeta potential of Ag NPs were characterized and identified. The Ag/mPEGTH, hybrid materials produced well dispersion and exhibit a remarkable superiority in enhancing the anticorrosion performance of epoxy coatings and fulfill a significant synergistic effect in anticorrosion and self-healing performance for epoxy composite coatings. The new self-healing mechanism of Ag/mPEGTH nanomaterial for the epoxy coating defects is tentatively proposed and discussed.
- Published
- 2018
18. Spectroscopic and computational evaluation on the binding of safranal with human serum albumin: Role of inner filter effect in fluorescence spectral correction
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Mohd. Sajid Ali and Hamad A. Al-Lohedan
- Subjects
Models, Molecular ,Circular dichroism ,Serum Albumin, Human ,02 engineering and technology ,010402 general chemistry ,Binding, Competitive ,01 natural sciences ,Protein Structure, Secondary ,Analytical Chemistry ,Hydrophobic effect ,chemistry.chemical_compound ,Dynamic light scattering ,Cyclohexenes ,Fluorescence Resonance Energy Transfer ,medicine ,Cluster Analysis ,Humans ,Instrumentation ,Spectroscopy ,Quenching (fluorescence) ,Terpenes ,Chemistry ,Hydrogen bond ,Circular Dichroism ,Hydrogen Bonding ,021001 nanoscience & nanotechnology ,Human serum albumin ,Fluorescence ,Dynamic Light Scattering ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Safranal ,Molecular Docking Simulation ,Spectrometry, Fluorescence ,Biophysics ,Thermodynamics ,Spectrophotometry, Ultraviolet ,0210 nano-technology ,Hydrophobic and Hydrophilic Interactions ,medicine.drug - Abstract
For determining the pharmacological properties of medicinal compounds, their binding with serum albumins is very crucial. Herein, we have selected safranal, a major constituent of saffron which is known to retain a number of medicinal properties including antioxidant, anti-inflammatory, tumoricidal, anti-genotoxic, and anti-aging activities; and studied its mechanism of binding with human serum albumin at physiological pH using various spectroscopic methods along with computational approach using molecular docking. A change in the difference UV-visible spectrum of HSA in presence of safranal was found which is due to the complex formation. Owing to the strong absorption of safranal at the fluorescence excitation wavelength of HSA (295 nm) and in the whole range of emission, the fluorescence spectra of HSA in presence of safranal were corrected for the inner filter effect. After the correction the spectra were free from the safranal absorption effect and it was found that addition of safranal causes the quenching of HSA fluorescence and a blue shift of the emission maximum which are attributed to the binding of safranal to the protein and dominance of hydrophobic forces in the interaction, respectively. It was evident from the comparison of observed and corrected fluorescence spectra that before correction there was a large red shift while after correction appearance of blue shift was occurred. The involvement of hydrophobic interaction was also found from the extrinsic fluorescence measurements using ANS dye as well as from the analyzed thermodynamic parameters. Safranal was found to partially induce the secondary structure of HSA as construed from the CD measurements. The size of the HSA was also decreased as evident from the DLS and RLS measurements. Both site marker studies and molecular docking simulations suggested that the primary binding site of the safranal in the HSA is Sudlow's site 1 located in the subdomain IIA. Hydrophobic interaction provides the major contribution to the binding forces along with a little amount of hydrogen bonding.
- Published
- 2018
19. New crosslinked poly (ionic liquid) cryogels for fast removal of methylene blue from waste water
- Author
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Ayman M. Atta, Ahmed M. Tawfeek, Sami A. Al-Hussain, Abdelrahman O. Ezzat, Ahmed I. Hashem, and Hamad A. Al-Lohedan
- Subjects
Polymers and Plastics ,General Chemical Engineering ,02 engineering and technology ,Sulfonic acid ,010402 general chemistry ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Adsorption ,Materials Chemistry ,medicine ,Environmental Chemistry ,Thermal stability ,Acrylic acid ,chemistry.chemical_classification ,Aqueous solution ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,Triethanolamine ,Ionic liquid ,Radical initiator ,0210 nano-technology ,medicine.drug - Abstract
New crosslinked Poly(ionic liquids), PILs, cryogels based on 2-acrylamido- 2-methylpropane sulfonic acid, AMPS, were prepared and copolymerized with acrylic acid, acrylamide or 2-hydroxyethyl methacrylate in the presence of triethanolamine. The crosslinking copolymerization of AMPS were carried in the presence of water at cooling temperature in the presence of amoniumpersulfate, N,N, N′, N′ tetramethylethylenediamine and N , N ′-methylenebisacrylamide as radical initiator, activator and crosslinker, respectively. The chemical structures, surface morphologies of the PILs cryogels were investigated. The PILs cryogels showed high thermal stability and interconnected pores. The cryogels achieved high adsorption capacity as 1228 mg·g −1 for removal of MB from aqueous solution during contact times ranged from 5 to 10 min. New mechanism for chemisorption of MB with the active centers of PIL cryogels is proposed and elucidated.
- Published
- 2018
20. Synthesis of MoS2 nanoparticle deposited graphene/mesoporous MnOx nanocomposite for high performance super capacitor application
- Author
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Shaban R.M. Sayed, S. K. Khadheer Basha, R. Jothi Ramalingam, L. John Kennedy, Dhaifallah Al-Dhayan, Niketha Konikkara, and Hamad A. Al-Lohedan
- Subjects
Supercapacitor ,Nanocomposite ,Materials science ,Renewable Energy, Sustainability and the Environment ,Graphene ,Oxide ,Energy Engineering and Power Technology ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,Substrate (electronics) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Chemical engineering ,law ,Molybdenum ,0210 nano-technology ,Mesoporous material - Abstract
The present study deal with the fabrication of low cost nanocomposite based electrodes based on Nickel foam binder free substrate for supercapacitor applications. The composition of nanocomposite is molybdenum sulphide nanoparticle/graphene coated on mesoporous manganese oxide. The first step is to involve the preparation of mesoporous manganese oxide by non-ionic surfactant assisted method. In the second stage is to deposit the reduced graphene on mesoporous manganese oxide in the presence of ultrasonic irradiation followed by addition of known quantity of commercial MoS2 nanopowder (particle size below 90 nm). The manganese oxide based nanocomposite is showing porous architecture with graphene sheet formation together with MoS2 nanoparticle deposition. N2 adsorption-desorption Isotherm curves for MoS2 nanoparticle (NP) modified graphene oxide/meso-MnO2 and pure meso-MnO2 displayed type IV isotherm with improved surface area values. The reduced graphene oxide (graphene) and MoS2 exist in the form of glassy flaky morphology as well as tubular/needle shapes are obtained after the deposition process in the final nanocomposite. The orderly arranged and anchored nano-sized mesoporous manganese oxide nanocomposites are showed increased specific capacitance (up to 527, 727 and 1160 F/g) and continuous cyclic stability.
- Published
- 2018
21. Reactive Mesoporous pH-Sensitive Amino-Functionalized Silica Nanoparticles for Efficient Removal of Coomassie Blue Dye
- Author
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Tahani Mazyad Almutairi, Ayman M. Atta, Abdelrahman O. Ezzat, Hamad A. Al-Lohedan, and Nourah I Sabeela
- Subjects
Materials science ,Aqueous solution ,General Chemical Engineering ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,Chemical engineering ,Dynamic light scattering ,nano-adsorbent ,Coomassie blue ,Zeta potential ,General Materials Science ,Amine gas treating ,Thermal stability ,nanoparticles ,amino-functionalized silica ,0210 nano-technology ,Mesoporous material ,Porosity ,mesoporous - Abstract
In this work, new smart mesoporous amine-functionalized silica nanoparticles were prepared from hydrolyzing microgels based on N-isopropyl acrylamide-co-vinyltrimethoxysilane microgels with tetraethoxysilicate and 3-aminopropyltriethoxysilane by sol-gel method. The thermal stability and Fourier transform infrared were used to determine the amine contents of the silica nanoparticles. The pH sensitivity of the synthesized silica nanoparticles in their aqueous solutions was evaluated by using dynamic light scattering (DLS) and zeta potential measurements. The porosity of the amine-functionalized silica nanoparticles was evaluated from a transmittance electron microscope and Brunauer-Emmett-Teller (BET) plot. The results have positively recommended the pH-sensitive amine-functionalized silica nanoparticles as one of the effective nano-adsorbent to remove 313 mg·, g&minus, 1 of CB-R250 water pollutant.
- Published
- 2019
22. Modified triazine decorated with Fe 3 O 4 and Ag/Ag 2 O nanoparticles for self-healing of steel epoxy coatings in seawater
- Author
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Abdelrahman O. Ezzat, Zeid A. Al Othman, Mahmood M. S. Abdullah, Hamad A. Al-Lohedan, Ayman M. Atta, and Ayman El-Faham
- Subjects
Materials science ,Reducing agent ,General Chemical Engineering ,Organic Chemistry ,Composite number ,Nanoparticle ,02 engineering and technology ,Epoxy ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Nanomaterials ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Surface charge ,0210 nano-technology ,Triazine - Abstract
New hybrid nanomaterials based on Fe 3 O 4 and Ag/Ag 2 O nanoparticles (NPs) supported by 2,4-dihydrazino-6-(methoxypolyethyleneglycol)-1,3,5-triazine (mPEGTH) were successfully synthesized without using reducing agents in both solution and solid phases. The mechanism for Fe 3 O 4 and Ag/Ag 2 O NPs formation in the presence of mPEGTH, their chemical structures, surface morphologies, crystal structures, thermal stabilities and mPEGTH contents were characterized and identified. The effects of seawater salinity and pH of solutions on the Fe 3 O 4 and Ag/Ag 2 O NPs surface charges and particle sizes distributions were examined to investigate their performances under aggressive conditions. It was found that, the Fe 3 O 4 /mPEGTH, hybrid nanomaterials obtained good dispersed NPs and exhibit a remarkable superiority in enhancing the anticorrosion performance of epoxy coatings more than Ag/Ag 2 O NPs. The Fe 3 O 4 /mPEGTH nanomaterials achieved significant synergistic effect to improve the anticorrosion and self-healing performances for epoxy composite coatings. They achieved higher salt spray resistance up to 1500 h without rust formation. The new self-healing mechanism of Fe 3 O 4 /mPEGTH nanomaterials was tentatively discussed.
- Published
- 2018
23. Cu II -Na I heteronuclear complex as anticancer entity against human breast cancer cell lines: DNA binding, cleavage, and Computational studies
- Author
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Ali Alsalme, Hamad A. Al-Lohedan, Farukh Arjmand, Mohammad Abul Farah, Khalid Mashay Al-Anazi, Mohd. Sajid Ali, Sartaj Tabassum, Rais Ahmad Khan, Mohammad Usman, and Musheer Ahmad
- Subjects
010405 organic chemistry ,Chemistry ,010402 general chemistry ,Cleavage (embryo) ,medicine.disease_cause ,01 natural sciences ,In vitro ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Apoptosis ,Cancer cell ,Materials Chemistry ,medicine ,Biophysics ,DNA fragmentation ,Viability assay ,Physical and Theoretical Chemistry ,DNA ,Genotoxicity - Abstract
Herein, we report the synthesis and structural investigation of CuII-NaI heterobimetallic complex 1, which comprises of the compartmental Schiff-base ligand (H2L) derived from DACH (1,2-Diaminocyclohexane) and o-vanillin. B3LYP/TZVP DFT calculation was performed to get a deeper insight of the ground state electronic structure, and quantitative analysis of non-covalent interactions was carried out using Hirshfeld surface analysis to explore H-bonding, C-H···π, Cu···C-H and Cu···H-C interactions. Furthermore, in vitro DNA binding studies with Complex 1 demonstrated the electrostatic mode of interaction at the major groove of the DNA. Complex 1 showed the oxidative damage of pBR322 DNA via ROS generation. Additionally, in vitro cytotoxicity and genotoxicity of complex 1 were investigated on human breast cancer cells (MCF-7), revealed concentration-dependent cell viability at micromolar concentration level. Flow cytometric analysis confirmed the cytotoxic potential of complex 1 as the percentage of apoptotic cells were increased in the treatment group. Genotoxicity was evident in the induction of micronucleus and DNA fragmentation.
- Published
- 2018
24. A zwitterionic Zn(II) benzothiazole nanohybrid conjugate as hydrolytic DNA cleavage agent
- Author
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Sartaj Tabassum, Hamad A. Al-Lohedan, Farukh Arjmand, and Siffeen Zehra
- Subjects
010405 organic chemistry ,Chemistry ,Chlorine atom ,Dna interaction ,Triclinic crystal system ,010402 general chemistry ,Cleavage (embryo) ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Hydrolysis ,chemistry.chemical_compound ,Dna cleavage ,Benzothiazole ,Polymer chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry ,Conjugate - Abstract
An organic–inorganic hybrid Zn(II) complex has been synthesized in a “zwitterionic” form which crystallizes in triclinic P1 space group possessing labile apical chlorine atoms. DNA interaction studies were performed to enunciate the binding strength. The hydrolytic cleavage potential of the complex was substantiated and the kinetic aspects of the mechanism followed are also discussed.
- Published
- 2018
25. Hydrothermal synthesis of nanosized (Fe, Co, Ni)-TiO2 for enhanced visible light photosensitive applications
- Author
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K. R. Anju, Hamad A. Al-Lohedan, Radika Thankapan, and Jothi Ramalignam Rajabathar
- Subjects
Anatase ,Materials science ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Hydrothermal circulation ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,symbols ,Water splitting ,Hydrothermal synthesis ,Crystallite ,Electrical and Electronic Engineering ,0210 nano-technology ,Raman spectroscopy ,Thermal analysis ,Visible spectrum - Abstract
Abstarct Nanosized TiO2 and various transition metal ions (Fe, Co and Ni) doped TiO2 were prepared through hydrothermal method. Thermal analysis confirms the formation of crystalline TiO2. The powder X-ray diffraction patterns of all the materials show crystalline anatase TiO2 with crystallite size in the range of 22–23 nm. Raman spectra show respective modes corresponding to anatase TiO2 and also it coincides with the XRD data. The DR UV–vis spectra of 0.01 (Fe-, Co-, Ni)-TiO2 extends to the visible region (450–650 nm). The extended absorbance of these materials into the visible region provides enhanced photosensitive applications under sunlight. The degradation rate of Methylene blue (MB) was used to evaluate the photosensitive activity under visible light irradiation. Results suggest that 0.01Fe- TiO2, 0.01Co- TiO2 and 0.01Ni-TiO2 materials can potential be used for the generation of future fuel hydrogen by water splitting using solar radiation.
- Published
- 2018
26. In situpreparation of magnetic Fe3O4.Cu2O.Fe3O4/cryogel nanocomposite powder via a reduction-coprecipitation method as adsorbent for methylene blue water pollutant
- Author
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Ayman M. Atta, Ahmed M. Tawfeek, Mona A. Ahmed, and Hamad A. Al-Lohedan
- Subjects
Nanocomposite ,Materials science ,Polymers and Plastics ,Coprecipitation ,Organic Chemistry ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Materials Chemistry ,Water treatment ,Particle size ,0210 nano-technology ,Methylene blue ,Sodium sulfite ,Nuclear chemistry - Published
- 2018
27. Antiproliferative activities of procainamide and its binding with calf thymus DNA through multi-spectroscopic and computational approaches
- Author
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Mohd. Sajid Ali, Khalid Mashay Al-Anazi, Hamad A. Al-Lohedan, and Mohammad Abul Farah
- Subjects
Circular dichroism ,Quenching (fluorescence) ,Chemistry ,Hydrogen bond ,Guanine ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Procainamide ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Hydrophobic effect ,Crystallography ,chemistry.chemical_compound ,Materials Chemistry ,medicine ,Molecular orbital ,Physical and Theoretical Chemistry ,0210 nano-technology ,HOMO/LUMO ,Spectroscopy ,medicine.drug - Abstract
The interaction between procainamide with ct-DNA was seen through several experimental and theoretical methods. The fluorescence intensity of procainamide decreased on increasing the concentration of ct-DNA and the quenching process was found to be static with approximately 1:1 binding between ct-DNA and procainamide. UV absorption spectroscopy gave an idea about minor groove binding which was further confirmed by the dye displacement method of DAPI/EtBr bounded ct-DNA interaction. Minor groove binding was also evidenced from the collective information obtained from DNA melting, viscosity and CD spectroscopy. Molecular docking simulations presented that procainamide bound in the minor groove (AT rich) region of B-DNA structures. From thermodynamic point of view the binding interaction between procainamide and ct-DNA was spontaneous process with liberation of energy and overall ordering of system. Hydrogen bonding was found to play important role as suggested by the values of thermodynamic parameters. Whereas from molecular docking simulations it was exposed that hydrogen bonding and hydrophobic interactions were crucial in the binding of ct-DNA and procainamide. DFT method was also used to calculate the Frontier molecular orbitals (HOMO and LUMO) of procainamide which were further used to calculate chemical potential (μ), chemical hardness (η) and fraction number of electrons (ΔN) from procainamide to DNA. Procainamide was found to act as electron donor to DNA bases excpet guanine. Finally, elucidation of anticancer activity revealed that procainamide possesses potential cytotoxicity against MCF-7 breast cancer cells and able to induce significant level of apoptosis at concentrations below IC50 value.
- Published
- 2018
28. Human serum albumin binding to the biologically active labdane diterpene 'leoheterin': Spectroscopic and in silico analysis
- Author
-
Mohd. Sajid Ali, Musarat Amina, Nawal M. Al Musayeib, and Hamad A. Al-Lohedan
- Subjects
Models, Molecular ,Stereochemistry ,Biophysics ,Serum Albumin, Human ,010402 general chemistry ,01 natural sciences ,Protein Structure, Secondary ,Hydrophobic effect ,Labdane ,chemistry.chemical_compound ,medicine ,Humans ,Computer Simulation ,Radiology, Nuclear Medicine and imaging ,Binding site ,Conformational isomerism ,Lamiaceae ,Radiation ,Quenching (fluorescence) ,Radiological and Ultrasound Technology ,010405 organic chemistry ,Chemistry ,Spectrum Analysis ,Plant Components, Aerial ,Human serum albumin ,0104 chemical sciences ,Molecular Docking Simulation ,Spectrometry, Fluorescence ,Drug Binding Site ,Diterpenes ,Diterpene ,medicine.drug - Abstract
Labdane diterpenes are important substances due to their remarkable biological activities such as, antibacterial, antiprotozoal, antifungal and cytostatic and cytotoxic effects against human cancer cells. We have isolated a labdane diterpene named “leoheterin” from the aerial parts of the Otostegia fruticosa Forssk (Briq) obtained from south west Arabian mountains of Saudi Arabia. The isolated compound was characterized by 1HNMR, 13CNMR, IR and UV–visible spectroscopies. Due to the pharmaceutical importance of this class of compounds we have studied the interaction of HSA with leoheterin by using several spectroscopic methods. The change in the UV spectrum of HSA in presence of leoheterin gives a primary idea about the interaction between them. Congruently, leoheterin quenches the fluorescence of HSA with a prominent blue shift of 5 nm, reminiscent of involvement of hydrophobic interactions. There was 1:1 binding between leoheterin and albumin which was taken place via static quenching mechanism. From CD it was revealed that leoheterin induces the secondary structure of HSA which is further supported by 3-d fluorescence measurements which shows a decrease in the size of the HSA-leoheterin complex as compared to the HSA alone. Molecular docking simulations presented that among the first three conformers, which have been arranged according to the least binding energies and are also in good corroboration with the free energies of binding obtained experimentally, the first two conformers shown the binding in hemin binding site of subdomain IB while in third conformer the binding site was near to the drug binding site 1 located in subdomain IIA. All conformers exhibited the involvement of hydrogen bonding as well as hydrophobic interactions.
- Published
- 2018
29. Synthesis, Characterization and Applications of Ethyl Cellulose-Based Polymeric Calcium(II) Hydrogen Phosphate Composite
- Author
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Hamad A. Al-Lohedan, Faruq Mohammad, and Tanvir Arfin
- Subjects
Metal ions in aqueous solution ,Composite number ,02 engineering and technology ,Electrolyte ,Conductivity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Adsorption ,Ethyl cellulose ,chemistry ,Chemical engineering ,Materials Chemistry ,Surface modification ,Electrical and Electronic Engineering ,0210 nano-technology - Abstract
The present report deals with the synthesis, characterization and testing of an ethyl cellulose–calcium(II) hydrogen phosphate (EC–CaHPO4) composite, where a sol–gel synthesis method was applied for the preparation of the composite so as to test its efficacy towards the electrochemical, biological, and adsorption related applications. The physical properties of the composite were characterized by using scanning electron microscopy (SEM), ultraviolet– visible (UV–Vis) spectroscopy, and fourier transform-infrared (FTIR) spectroscopy. On testing, the mechanical properties indicated that the composite is highly stable due to the cross-linked rigid framework and the enhanced interactions offered by the EC polymer supported for its binding very effectively. In addition, the conductivity of EC–CaHPO4 is completely governed by the transport mechanism where the electrolyte concentration has preference towards the adsorption of ions and the variations in the conductivity significantly affected the material’s performance. We observed an increasing order of KCl > NaCl for the conductivity when 1:1 electrolytes were applied. Further, the material was tested for its usefulness towards the purification of industrial waste waters by removing harmful metal ions from the samples collected near the Aligarh city, India where the data indicates that the material has highest affinity towards Pb2+, Cu2+, Ni2+ and Fe3+ metal ions. Finally, the biological efficiency of the material was confirmed by means of testing the antibacterial activity against two gram positive (staphylococcus aureus and Bacillus thuringiensis) and two gram negative bacteriums (Pseudomonas aeruginosa and Patoea dispersa). Thus, from the cumulative study of outcomes, it indicates that the EC–CaHPO4 composite found to serve as a potential smart biomaterial due to its efficiency in many different applications that includes the electrical conductivity, adsorption capability, and antimicrobial activity.
- Published
- 2018
30. Synthesis and Application of Amphiphilic Poly(ionic liquid) Dendron from Cashew Nut Shell Oil as a Green Oilfield Chemical for Heavy Petroleum Crude Oil Emulsion
- Author
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Hamad A. Al-Lohedan, Mahmood M. S. Abdullah, Amany Gaffer, and Ayman M. Atta
- Subjects
Cardanol ,Aqueous solution ,General Chemical Engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Dispersant ,0104 chemical sciences ,chemistry.chemical_compound ,Fuel Technology ,Ethanolamine ,chemistry ,Chemical engineering ,Emulsion ,Ionic liquid ,Petroleum ,0210 nano-technology ,Asphaltene - Abstract
The green chemicals based on bio-surface-active ionic liquids attracted great attention in the petroleum industry as a result of their high efficiency as multipurpose additives for the petroleum crude oils and their products. In the present work, the chemical structure of cardanol produced from cashew nut shell oil was modified and etherified with epichlorohydrine, tetraethylene glycol, and ethanolamine to produce branched non-ionic surfactants. The amine groups of the cardanoxy ethoxy branches were quaternized and polymerized using 2-acrylamido-2-methylpropane sulfonic acid to produce dendritic protic ionic liquid. The chemical structure, surface activity, ζ potential, and aggregation characteristics of the new modified dendritic non-ionic cardanoxy polyphenol and its poly(ionic liquid) in aqueous solution were analyzed and identified. Their applications as asphaltene dispersants and demulsifiers for the heavy petroleum crude oil emulsions were investigated to confirm their promising performances.
- Published
- 2018
31. In situpreparation of magnetite/cuprous oxide/poly(AMPS/NIPAm) for removal of methylene blue from waste water
- Author
-
Abdelrhman O. Ezzat, Ahmed M. Tawfeek, Talal Al-Otabi, Sami A. Al-Hussain, Ayman M. Atta, and Hamad A. Al-Lohedan
- Subjects
Materials science ,Polymers and Plastics ,Organic Chemistry ,Oxide ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Chemical engineering ,Wastewater ,Materials Chemistry ,Water treatment ,Sewage treatment ,0210 nano-technology ,Methylene blue ,Magnetite - Published
- 2018
32. Synthesis and application of new surface active poly (ionic liquids) based on 1,3-dialkylimidazolium as demulsifiers for heavy petroleum crude oil emulsions
- Author
-
Ayman M. Atta, Hamad A. Al-Lohedan, Ahmed I. Hashem, and Abdelrahman O. Ezzat
- Subjects
chemistry.chemical_classification ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Toluene ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Surface tension ,chemistry.chemical_compound ,Adsorption ,chemistry ,Dynamic light scattering ,Chemical engineering ,Ionic liquid ,Emulsion ,Materials Chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology ,Spectroscopy ,Asphaltene - Abstract
Application of ionic liquids (ILs) and their polymers (PILs) as green chemicals in the petroleum industry is an original area of the research study. This work aims to synthesize new amphiphilic ILs based on dialkyl substituted imidazolium cations as a head groups combine with acetate and 4-(trifluoromethoxy) phenyl borate anions. Their surface activity and aggregation behaviors, in toluene and aqueous medium, have been investigated by surface tension, particle size distribution and zeta potentials measurements. The sizes of aggregates in water and toluene solvents have been investigated from the dynamic light scattering (DLS) measurements. The demulsification mechanism for the heavy crude oil/water emulsions at low water contents has been estimated from the fluorescent optical microscope in the presence of the prepared ILs and PILs. The demulsification performance of ILs and PILs demulsifiers was found to be considerably improved with incorporation of oxyethylene units into hydrophobic imidazolium cations, and increment the content of 4-(trifluoromethoxy)phenyl borate anions. The results confirmed that the PIL has stronger adsorption for asphaltene molecules facilitated the distortion of the asphaltene protective film that stabilized the water-in-oil emulsion and thus promoting the water droplets coalescence to realize the separation of water from oil.
- Published
- 2018
33. Anti-cancer activity of hierarchical ZSM-5 zeolites synthesized from rice-based waste materials
- Author
-
Hamad A. Al-Lohedan, K. Kaviyarasu, R. Jothi Ramalingam, J. Judith Vijaya, S. K. Jesudoss, and L. John Kennedy
- Subjects
Thermogravimetric analysis ,Materials science ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Amorphous solid ,law.invention ,Crystallinity ,Adsorption ,Chemical engineering ,law ,Desorption ,Calcination ,ZSM-5 ,0210 nano-technology ,Zeolite - Abstract
Herein, organic template-free MFI-type ZSM-5 zeolites were successfully synthesized by the hydrothermal method using waste materials such as rice husk ash (RHA), rice hull ash (RHuA), and rice straw ash (RSA). The waste materials were locally obtained, precleaned, and properly heat-treated to produce a high-purity crystalline SiO2 that was used in the synthesis of ZSM-5 zeolites under autogenous pressure in a short reaction time (5 days). The mineralogical phases, morphology, textural and thermal properties of the synthesized products were investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Raman spectroscopy, high-resolution scanning electron microscopy (HR-SEM), N2 adsorption/desorption isotherms (BET), temperature-programmed desorption (NH3-TPD), and thermogravimetric analysis (TGA/DTA). The as-synthesized ZSM-5 zeolites showed good crystallinity, and no amorphous material existed in the framework of the ZSM-5 zeolites after calcination and ammonium exchange processes. The characterization results prove that the high crystallinity of RHA as compared to that of the other materials (RHuA and RSA) is due to the high silica content in RHA. The transformation occurs from high-crystallinity RHA into ZSM-5 zeolite and also increases the crystallinity of zeolites. In addition, we have investigated hierarchical ZSM-5 zeolites at various concentrations for their potential cytotoxicity effect against the human lung epithelial cancer A549 cells.
- Published
- 2018
34. Okra extract-assisted green synthesis of CoFe2O4 nanoparticles and their optical, magnetic, and antimicrobial properties
- Author
-
K. Kombaiah, J. Judith Vijaya, L. John Kennedy, R. Jothi Ramalingam, Hamad A. Al-Lohedan, and M. Bououdina
- Subjects
Photoluminescence ,Materials science ,Band gap ,Analytical chemistry ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Crystallinity ,chemistry ,General Materials Science ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Spectroscopy ,Cobalt ,Microwave ,Nuclear chemistry - Abstract
Cobalt ferrite nanoparticles are synthesized using biological agents as fuel by both conventional and microwave heating methods. We focused on the green synthesis of cobalt ferrite, which is eco friendly, inexpensive, and easy to produce by large-scale synthesis. Synthesis methods were carried out under the same conditions. The role of the plant extract and advantages of microwave techniques are discussed. Plant extract-mediated nanoparticles were characterized by various techniques to analyze the size, shape, crystallinity, optical, magnetic, and antimicrobial properties. The X-ray diffraction pattern revealed single-phase crystalline structures with an average size of 45–55 nm. The functional groups present in the samples were confirmed by Fourier transform infrared spectroscopy. From SEM and DLS studies, it is confirmed that the spherical nanoparticles range in the size of 300–500 nm for CHM and 5–50 nm for MHM. Energy-dispersive X-ray spectroscopy analysis confirmed the presence of cobalt, iron, and oxygen. The energy band gap of the samples was measured by UV–Visible diffuse reflection spectroscopy. In photoluminescence analysis, the band emission was observed in the visible region. Samples prepared by microwave heating showed better magnetic behavior than those prepared by conventional heating based on vibrating sample magnetometer analysis. The plant extract makes the synthesis of cobalt ferrite nanoparticles a potentially low-cost and ecofriendly remediation method. The synthesized nanoparticles also exhibited excellent antimicrobial activity against bacteria and fungus strains.
- Published
- 2018
35. Highly efficient green mesostructured urea functionalized on SBA-15 catalysts for selective synthesis of benzlidenemalononitrile
- Author
-
Hamad A. Al-Lohedan, Jimmy Nelson Appaturi, R. Jothi Ramalingam, and Mohd Rafie Johan
- Subjects
010405 organic chemistry ,Chemistry ,Acetylacetone ,General Chemistry ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Dry media reaction ,Benzaldehyde ,chemistry.chemical_compound ,Mechanics of Materials ,Yield (chemistry) ,Organic chemistry ,General Materials Science ,Knoevenagel condensation ,Mesoporous material ,Nuclear chemistry ,Malononitrile - Abstract
A series of urea-immobilized SBA-15 catalysts were synthesized via post grafting method using 3-chloropropyltriethoxysilane (CPTES) as the anchoring agent. The solid catalyst was characterized by PXRD, N 2 adsorption-desorption, FT-IR, elemental analyzer, TEM, CO 2 -TPD and 29 Si CP/MAS NMR. Detailed analysis of the pore size illustrated the mesoporous nature of the immobilized catalyst. The as-prepared catalyst was further evaluated in the Knoevenagel condensation reaction under different reaction conditions. Benzaldehyde was employed in the Knoevenagel condensation reaction with malononitrile. Catalytic results showed that the Urea(4.8)/SBA-15 exhibits high efficacy (98% of yield) for promoting this reaction at 40 °C and in the absence of a solvent. Under the same reaction conditions, acetylacetone led to a lower benzaldehyde conversion of 10%, whereas ethyl cyanoacetate provides up to 88% conversion. The catalyst could be recycled and reused for at least five reaction cycles with slight loss of catalytic activity.
- Published
- 2018
36. Synthesis and Application of Poly(ionic liquid) Based on Cardanol as Demulsifier for Heavy Crude Oil Water Emulsions
- Author
-
Mahmood M. S. Abdullah, Hamad A. Al-Lohedan, Ayman M. Atta, Ahmed I. Hashem, and Abdelrahaman O. Ezzat
- Subjects
chemistry.chemical_classification ,Diethanolamine ,Cardanol ,Chemistry ,General Chemical Engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Demulsifier ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Fuel Technology ,Ethanolamine ,Amphiphile ,Ionic liquid ,Organic chemistry ,0210 nano-technology ,Alkyl ,Asphaltene - Abstract
Amphiphilic poly(ionic liquids), PILs, derived from natural products attracted great attention as a green chemical in the field of the surface chemistry and petroleum industry. In the present work, new surface active PILs were synthesized from cardanol cashew nut oil as a hydrophobic alkyl phenol. The phenol group was etherified with diethanolamine, ethanolamine, and tetraethylene glycol using linking agent based on β,β-dicholorodiethyl ether to insert nonionic hydrophilic groups into cardanol. The amine group was quaternized with 2-acrylamido-2-methyl-1-propanesulfonic acid to produce polymerizable ionic liquids that polymerized to obtain new PILs. The chemical structure of the prepared new PILs was elucidated from 1HNMR and elemental analysis. The surface activity of the prepared PILs was determined from the surface and interfacial tension measurements of their aqueous solution. The ability of the prepared PILs to disperse the asphaltene fractions of the heavy Arabian crude oil was studied. It was used ...
- Published
- 2017
37. Bioreduction potentials of dried root of Zingiber officinale for a simple green synthesis of silver nanoparticles: Antibacterial studies
- Author
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L. John Kennedy, K. Kaviyarasu, Malik Maaza, Hamad A. Al-Lohedan, R. Jothi Ramalingam, J. Judith Vijaya, N. Jayaprakash, K. Kombaiah, and V M Mansoor-Ali
- Subjects
Silver ,Scanning electron microscope ,education ,Biophysics ,Analytical chemistry ,Metal Nanoparticles ,02 engineering and technology ,Ginger ,010402 general chemistry ,Plant Roots ,01 natural sciences ,Silver nanoparticle ,Crystallinity ,Microscopy, Electron, Transmission ,X-Ray Diffraction ,Gram-Negative Bacteria ,Spectroscopy, Fourier Transform Infrared ,Radiology, Nuclear Medicine and imaging ,Particle Size ,Radiation ,Radiological and Ultrasound Technology ,Plant Extracts ,Chemistry ,Spectrometry, X-Ray Emission ,Green Chemistry Technology ,Electrochemical Techniques ,021001 nanoscience & nanotechnology ,Anti-Bacterial Agents ,0104 chemical sciences ,Transmission electron microscopy ,Microscopy, Electron, Scanning ,Crystallite ,Selected area diffraction ,Cyclic voltammetry ,0210 nano-technology ,Antibacterial activity ,Nuclear chemistry - Abstract
Green synthesis of silver nanoparticles (Ag NPs) using an extract of dried Zingiber officinale (ginger) root as a reducing and capping agent in the presence of microwave irradiation was herein reported for the first time. The formation of symmetrical spheres is confirmed from the UV-Visible spectrum of Ag NPs. Fourier transform infra-red spectroscopy confirms the formation of the Ag NPs. X-ray diffraction analysis was utilized to calculate the crystallite size of Ag NPs and the value was found to be 10nm. High-resolution transmission electron microscopy and high-resolution scanning electron microscopy were used to investigate the morphology and size of the synthesized samples. The sphere like morphology is confirmed from the images. The purity and crystallinity of Ag NPs is confirmed by energy-dispersive X-Ray analysis and selected area electron diffraction respectively. The electrochemical behavior of the synthesized Ag NPs was assessed by cyclic voltammetry (CV) and shows the redox peaks in the potential range of -1.1 to +1.1V. Agar diffusion method is used to examine the antibacterial activity of Ag NPs. For this purpose, two gram positive and two gram negative bacteria were studied. This single step approach was found to be simple, short time, cost-effective, reproducible, and eco-friendly.
- Published
- 2017
38. Molecular interactions of cefoperazone with bovine serum albumin: Extensive experimental and computational investigations
- Author
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Mohd. Sajid Ali, Hamad A. Al-Lohedan, Monika Jain, Teresa Santos-Silva, Noura Saad Al-Shuail, and Jayaraman Muthukumaran
- Subjects
Quenching (fluorescence) ,biology ,Hydrogen bond ,Chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Fluorescence ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Hydrophobic effect ,Protein structure ,Materials Chemistry ,biology.protein ,Biophysics ,Physical and Theoretical Chemistry ,Binding site ,Bovine serum albumin ,0210 nano-technology ,Spectroscopy - Abstract
We investigated the binding of the cephalosporin-class drug cefoperazone (CFP) with bovine serum albumin (BSA) using spectroscopic techniques and in silico methods. The aim of this study was to (i) emphasize the importance of correcting for the inner filter effect in this type of study and (ii) understand the binding mechanism of CFP with BSA by addressing protein conformation and plausible binding sites. Formation of the complex was confirmed by UV–visible spectroscopy. Quenching of BSA fluorescence in the presence of CFP was also observed. Because of the high absorption of CFP in the fluorescence emission range of BSA, the fluorescence emission spectra were corrected for the inner filter effect. Fluorescence emission was studied at excitation wavelengths of 280 and 295 nm. The uncorrected data showed a significant contribution of tyrosine at the excitation wavelength of 280 nm; however, after correction, this contribution became negligible. The static-type mechanism was found to be involved in quenching, with almost 1:1 binding between BSA and CFP. Hydrogen bonding and hydrophobic forces were found to dominate the protein–ligand interactions with a slight decrease in the α-helical contents. Synchronous fluorescence spectral data (at Δλ = 15 and 60 nm) were also corrected for the inner filter effect, with the results being similar to those of excitation at 280 and 295 nm. Molecular docking and molecular dynamics (MD) simulation results suggest that, apart from the two known drug binding sites (drug site I and II), one putative binding site (binding site III) located between BSA domains 1 and 3 was also possible for CFP. MD simulations of the previously reported drug binding sites (drug site I and II) and putative binding site III revealed that binding site III showed excellent binding profiles and could be a target for future research related to BSA-drug binding.
- Published
- 2021
39. Magnetite doped cuprous oxide nanoparticles as modifier for epoxy organic coating
- Author
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Reda S. Abdel Hameed, Hamad A. Al-Lohedan, Ayman M. Atta, Abdelrhman O. Ezzat, and Ahmed I. Hashem
- Subjects
Materials science ,General Chemical Engineering ,Nanoparticle ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Nanomaterials ,chemistry.chemical_compound ,Adsorption ,Coating ,Materials Chemistry ,Zeta potential ,Composite material ,Nanocomposite ,Organic Chemistry ,Epoxy ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry ,visual_art ,Ionic liquid ,visual_art.visual_art_medium ,engineering ,0210 nano-technology - Abstract
In this paper, a novel in-situ preparation method of multipurpose additives based on Cu2O·2Fe3O4 nanocomposite is presented. Cu2O·2Fe3O4 nanocomposites were synthesized in large quantities by a simple and facile one-step co-precipitation method in the presence of poly(ionic liquid). The prepared Cu2O·2Fe3O4 nanomaterials were applied as multipurpose epoxy coating additive to improve its coating performances as marine coatings of steel. The nanocomposites were characterized by FTIR, XRD, SEM, TEM, and DLS techniques. The incorporation of poly (ionic liquid) into Cu2O·2Fe3O4 nanocomposites reduced the particle size, increased the porosity and zeta potential, leading to improve of the adsorption sites and affinity toward interaction with epoxy coatings. The Cu2O·2Fe3O4 nanocomposites improved the adhesion strength, mechanical stability and self—healing characteristic and the flame retardancy with decreasing the total smoke production of epoxy coatings with steel.
- Published
- 2017
40. Synthesis and bio-physical characterization of Silver nanoparticle and Ag-mesoporous MnO2 nanocomposite for anti-microbial and anti-cancer activity
- Author
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Mansoor-Ali Vaali-Mohammed, Hamad A. Al-Lohedan, R. Jothi Ramalingam, and Jimmy Nelson Appaturi
- Subjects
Nanocomposite ,Reducing agent ,Chemistry ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Silver nanoparticle ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Transmission electron microscopy ,Materials Chemistry ,Particle size ,Physical and Theoretical Chemistry ,0210 nano-technology ,Mesoporous material ,Antibacterial activity ,Spectroscopy ,Nuclear chemistry - Abstract
In the present study, a unique precursor source and plant extract have been developed for biogenic synthesis of silver nanoparticles (AgNPs) using different silver precursor solutions. Mesoporous-MnO2 nanocomposites (before doping AgNPs in meso-MnO2) were prepared using anon-ionic surfactant (Triton X-100) and the antibacterial activity of the prepared sample was analyzed against various bacterial pathogens. The plant leaf extract of Alternanthera bettzickiana was used as a reducing agent. A fast ultra-sonication-assisted process facilitated the incorporation of AgNPs on mesoporous MnOx. Different type of silver precursor has been used to prepare the biogenic AgNPs for the first time. Particle sizes of AgNPs were obtained below 5–10 nm. Surface area, morphology, crystalline phase, and particle size of the synthesized nanoparticles were characterized by X-ray diffraction (XRD), Brunauer, Emmett, Teller (BET)/Barrett, Joyner, Halenda (BJH)method, Scanning Electron Microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM) techniques. The antibacterial activity of biogenic AgNPs and AgNPs@meso-MnO2 were tested against gram-positive (Staphylococcus aureus and Streptococcus mutans) and gram-negative (Salmonella typhi, Escherichia coli and Pseudomonas aeruginosa) bacteria using the well diffusion assay. All samples including biogenic AgNPs and AgNPs@meso-MnO2 showed effective inhibition zones against all pathogens and no activity was observed for control and bulk meso-MnO2. Preliminary studies related to the anti-cancer activity of the prepared AgNPs have also been studied and compared for different route prepared silver nanoparticles.
- Published
- 2017
41. Green synthesis of biogenic silver nanoparticles using Solanum tuberosum extract and their interaction with human serum albumin: Evidence of 'corona' formation through a multi-spectroscopic and molecular docking analysis
- Author
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Mohammad Altaf, Mohd. Sajid Ali, and Hamad A. Al-Lohedan
- Subjects
Circular dichroism ,Silver ,Absorption spectroscopy ,Biophysics ,Serum albumin ,Metal Nanoparticles ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Protein Structure, Secondary ,Silver nanoparticle ,Dynamic light scattering ,Spectroscopy, Fourier Transform Infrared ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Particle Size ,Serum Albumin ,Solanum tuberosum ,Binding Sites ,Radiation ,Chromatography ,Radiological and Ultrasound Technology ,biology ,Chemistry ,Circular Dichroism ,Cooperative binding ,Green Chemistry Technology ,021001 nanoscience & nanotechnology ,Human serum albumin ,Dynamic Light Scattering ,0104 chemical sciences ,Molecular Docking Simulation ,biology.protein ,Thermodynamics ,Spectrophotometry, Ultraviolet ,0210 nano-technology ,Protein Binding ,medicine.drug - Abstract
Biogenic silver nanoparticles (AgNPs) have been synthesized by using Solanum tuberosum (potato) extract (PE) as a reducing as well as stabilizing agent which is reasonably cheaper, non-toxic and easily available material. The green synthesis of silver nanoparticles has been carried out by very simple method and the nanoparticles were characterized by surface plasmon band as well as TEM measurements. The PE-AgNPs were highly dispersed in the solution and found to be spherical with around 10nm in size. Interaction of these nanoparticles was studied with plasma protein HSA by means of various spectroscopies, such as, UV-visible, fluorescence, DLS, CD and FTIR spectroscopies. The HSA was found to form the protein "corona" around the starch-capped PE-AgNPs. Absorption spectroscopy revealed that the interaction between HSA and PE-AgNPs resulted in the ground state complex formation. Due to the strong absorption of PE-AgNPs, the inner filter effect was corrected for the fluorescence data. PE-AgNPs were found to quench the fluorescence of HSA with a small blue shift attributed to the increase in the hydrophobicity near tryptophan residue due to the presence of amylopectin and amylose units in the starch. The value of n, Hill's constant, was found to be >1 which determines the existence of a cooperative binding between nanoparticle and albumin. Several parameters such as Stern-Volmer and binding constants in addition to the thermodynamic parameters have been analyzed and discussed which established that the complex formation has taken place via static quenching mechanism and the corona formation between albumin and PE-AgNPs was entropy driven process. Binding of biogenic PE-AgNPs to the HSA slightly affected the secondary structure of latter with a small decrease in α-helical contents resulting in the partial unfolding of the protein, though the structural motif remained the same. Molecular docking simulations revealed various possible binding modes between PE-AgNPs and albumin.
- Published
- 2017
42. Synthesis, characterization and catalytic activity of melamine immobilized MCM-41 for condensation reactions
- Author
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Hamad A. Al-Lohedan, R. Jothi Ramalingam, and Jimmy Nelson Appaturi
- Subjects
Mechanical Engineering ,Acetylacetone ,Inorganic chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensation reaction ,Furfural ,01 natural sciences ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,MCM-41 ,Mechanics of Materials ,General Materials Science ,Knoevenagel condensation ,0210 nano-technology ,Melamine ,Selectivity ,Nuclear chemistry - Abstract
In the present study, melamine immobilized MCM-41 is synthesized by grafting on modified MCM-41. The surface area, pore size and pore volume of MCM-41-Mela were found to be decreased after immobilization of melamine. FTIR and Raman spectroscopy results revealed the successful grafting of melamine on the surface of MCM-41. The 29Si CP/MAS NMR of MCM-41-Mela showed the existence of T2, T3, Q3 and Q4 silicon centres. The catalytic activities were investigated through a liquid phase Knoevenagel condensation reaction between furfural and acetylacetone. A conversion of 93.1% was achieved with 100% selectivity towards 3-(2-furylmethylene)-2,4-pentanedione (FMP) under solvent-free condition. The catalytic activity of MCM-41-Mela was then successfully carried out for Knoevenagel condensation with different substrates, giving excellent yields of the corresponding products. The catalyst was easily regenerated and could be reused for three times without loss of catalytic activity. Simple preparation methods, high efficiency and reusability of the heterogeneous MCM-41-Mela catalyst demonstrate a great potential for future catalysis application.
- Published
- 2017
43. Comparative investigation on the structural, morphological, optical, and magnetic properties of CoFe2O4 nanoparticles
- Author
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M. Bououdina, R. Jothi Ramalingam, J. Judith Vijaya, K. Kombaiah, L. John Kennedy, and Hamad A. Al-Lohedan
- Subjects
Potential well ,Photoluminescence ,Materials science ,Band gap ,Process Chemistry and Technology ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,Ferromagnetism ,Materials Chemistry ,Ceramics and Composites ,Crystallite ,0210 nano-technology ,Microwave - Abstract
Herein, we report a sustainable production of magnetic cobalt ferrite nanoparticles by conventional (CHM) and microwave heating (MHM) method. Hibiscus rosa-sinensis extract was used as both reducing and stabilizing agent. Using plant extracts to synthesize nanoparticles has been considered as an eco-friendly method, since it avoids noxious chemicals. The plethora of plant extract mediated nanoparticles were compared by techniques, such as XRD, Rietveld, FT-IR, SEM, EDX, UV-Visible DRS, PL and VSM were carried out to analyze and understand their crystallite size, functional groups, morphology, optical and magnetic properties. The crystalline structure of cobalt ferrite nanoparticles revealed the cubic structure and the microwave heating of nanoparticles showed smaller crystallite size compared to the conventional heating, which was then confirmed by XRD analysis. To analyze the presence of functional groups and the phytochemical involvement of the plant extract was confirmed by FT-IR studies. Spherical morphology with less than 100 nm sized particles was confirmed by SEM and EDX analysis confirm the existence of Co, O, and Fe elements present in the samples. UV-Visible DRS studies were carried out to calculate the band gap of the as-synthesized nanoparticles, estimated from the Kubelka-Munk function, as 2.06, and 1.87 eV for CHM and MHM, respectively. Photoluminescence emission spectrum of the nanoparticles showed two different bands at 494 and 620 nm, which explores the optical properties of the nanoparticles, due to the quantum confinement effect. VSM analysis showed better ferromagnetic behavior, which can be used for magnetic applications.
- Published
- 2017
44. Catalytic conversion of polyols (sorbitol and xylitol) to hydrocarbons over hierarchical ZSM-5 zeolite catalysts in a fixed bed reactor
- Author
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Subramanian Sivasanker, Ahmed M. Tawfeek, R. Jothiramalingam, L. John Kennedy, C. Ragupathi, J. Judith Vijaya, S. Narayanan, T.M. Sankaranarayanan, and Hamad A. Al-Lohedan
- Subjects
Atmospheric pressure ,010405 organic chemistry ,Fixed bed ,010402 general chemistry ,Xylitol ,01 natural sciences ,Substrate concentration ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Organic chemistry ,Sorbitol ,Physical and Theoretical Chemistry ,ZSM-5 zeolite ,Space velocity - Abstract
The catalytic activity of hierarchical ZSM-5 zeolites was investigated in the polyols (sorbitol and xylitol) to hydrocarbons conversion in a fixed bed reactor under atmospheric pressure by altering different parameters. A lower sorbitol and xylitol conversion was achieved at the reaction temperature of 375 °C, whereas a higher value of 92.33 and 88.19% sorbitol conversion, 95.58 and 92.32% xylitol conversion was obtained when the reaction temperature was further elevated to 425 °C for ZSM-5-WS(28) and ZSM-5-WOS(28) catalysts. Other important parameters, such as substrate concentration, weight hourly space velocity (WHSV) and Si/Al ratio strongly influenced the polyols to hydrocarbons conversion reaction. The optimal conditions are substrate concentration (sorbitol/xylitol) of 15%, WHSV of 1.0 h−1, reaction temperature of 425 °C. In addition to that, the recycling performances of the ZSM-5 catalysts were carried out for four runs and the catalysts were showed better recycling performance and stability.
- Published
- 2017
45. Luteinizing hormone-releasing hormone targeted superparamagnetic gold nanoshells for a combination therapy of hyperthermia and controlled drug delivery
- Author
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Hamad A. Al-Lohedan and Faruq Mohammad
- Subjects
Hyperthermia ,Materials science ,Composite number ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Gonadotropin-Releasing Hormone ,Biomaterials ,chemistry.chemical_compound ,Drug Delivery Systems ,Nuclear magnetic resonance ,law ,medicine ,Magnetite Nanoparticles ,High-resolution transmission electron microscopy ,Nanoshells ,021001 nanoscience & nanotechnology ,medicine.disease ,Controlled release ,0104 chemical sciences ,SQUID ,chemistry ,Mechanics of Materials ,Drug delivery ,Gold ,0210 nano-technology ,Iron oxide nanoparticles ,Superparamagnetism ,Nuclear chemistry - Abstract
In this, we developed superparamagnetic iron oxide nanoparticles (SPIONs) to be appropriate for the diagnosis and treatment of cancer cells by means of magnetic resonance imaging (MRI) and magnetically controlled hyperthermia/drug delivery (respectively). For the preparation of composite, we started with SPIONs, followed by its coating with gold to form SPIONs@Au, which further conjugated with luteinizing hormone-releasing hormone (LHRH) protein by making use of the cysteamine (Cyst) space linker and finally loaded with 5-Fluororacil (5-Fu) anticancer drug to form SPIONs@Au-Cyst-LHRH_5-Fu composite. Thus formed composite was thoroughly characterized by making use of the instrumental analysis such as HRTEM, EDAX, DLS, TGA, XPS, UV-vis, FTIR, HPLC and SQUID magnetics. We found from the analysis that the particles are spherical in shape, monodispersed with a size distribution of around 6.9nm in powdered dry form, while in solution phase it is 8.7nm. The UV-vis, FTIR, and HPLC studies confirmed for the loading of the 5-Fu drug onto the surface of SPIONs core and the maximum amount of drug that got adsorbed to be about 42%. The SQUID magnetic studies provided the information for the superparamagnetic behavior of the drug loaded SPIONs and the saturation magnetization (Ms) values observed to be about 11emu/g and the blocking temperature (TB) of 348K. On testing the particles to see the effects of magnetic fluid hyperthermia (MFH) due to some changes in the solvent medium and oscillating frequency, the material seems to be highly active in aqueous medium and the activity gets increased with respect to the applied frequency of oscillation (430Hz>230Hz>44Hz). From the heat release studies, the calculated specific power loss (SPL) values for the SPIONs@Au-Cyst-LHRH_5-Fu composite are at the highest of 1068W/g in water (430Hz) vs the least of 68W/g in toluene (44Hz). Further, the drug release studies tested under the influence of magnetic field provided the information that the composite released its entire loaded drug following an exposure to the magnetic field (430Hz over 4h time), while only 53% (over 5h) for the controlled measurements of no magnetic field, thereby supporting to have the magnetic field so as to observe the externally controlled drug release effects. Finally, the results of the study provide the information that the SPIONs@Au-Cyst-LHRH_5-Fu composite can be potential for theranostic applications of cancer through the phenomenon of applying for MRI, magnetically controlled hyperthermia and drug delivery externally.
- Published
- 2017
46. Silver nanoparticle/r-graphene oxide deposited mesoporous-manganese oxide nanocomposite for pollutant removal and supercapacitor applications
- Author
-
Arun Kumar Shukla, Aldalbahi Ali, Hamad A. Al-Lohedan, and Jothi Ramalingam Rajabathar
- Subjects
Materials science ,Nanocomposite ,Renewable Energy, Sustainability and the Environment ,Graphene ,Inorganic chemistry ,Oxide ,Energy Engineering and Power Technology ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Silver nanoparticle ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Mesoporous organosilica ,Fuel Technology ,chemistry ,Chemical engineering ,law ,0210 nano-technology ,Mesoporous material ,Graphene oxide paper - Abstract
Mesoporous manganese oxide was prepared by a non-ionic surfactant route using Triton X-100, followed by Ag nanoparticle (NP) and graphene oxide incorporation by an ultra-sonication-assisted process. Fine Ag NPs were incorporated into the tubular texture of mesoporous manganese oxide. The crystalline phase, particle size, and morphology of the prepared materials were characterized by X-ray diffraction (XRD), Barrett–Joyner–Halenda–Brunauer–Emmett–Teller analysis, scanning electron microscopy–energy dispersive X-ray analysis, and high-resolution transmission electron microscopy (HR-TEM). The XRD results confirmed the formation of the Mn2O3 phase for the as-prepared mesoporous manganese oxide and its nanocomposite. Very fine Ag NPs ( 98% removal of Cr(VI) within 1–2 h of reaction time) for Ag NP-incorporated mesoporous MnO2. Efficient activity was observed because of the fine Ag NPs present in mesoporous manganese oxide, as opposed to the case of graphene oxide-doped meso-MnO2 and pristine mesoporous meso-MnO2.
- Published
- 2017
47. Synthesis of zinc oxide nanocomposites using poly (ionic liquids) based on quaternary ammonium acrylamidomethyl propane sulfonate for water treatment
- Author
-
Ahmed M. Tawfik, Ayman M. Atta, Hamad A. Al-Lohedan, Abdelrhman O. Ezzat, and Ahmed I. Hashem
- Subjects
Materials science ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,Zinc ,Sulfonic acid ,010402 general chemistry ,01 natural sciences ,Nanomaterials ,chemistry.chemical_compound ,Adsorption ,Materials Chemistry ,Physical and Theoretical Chemistry ,Spectroscopy ,chemistry.chemical_classification ,Nanocomposite ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Sulfonate ,chemistry ,Chemical engineering ,Ionic liquid ,Water treatment ,0210 nano-technology - Abstract
Antimicrobial zinc oxide (ZnO) nano-sized materials have been used as environmentally friendly nanocomposites for water treatment applications due to their superior properties. Their particle size growth in water is one of their limitations that affects their preparation as nano-sized ZnO in aqueous medium at room temperature. In the present work, poly(ionic liquid), PIL, based on quaternary ammonium salts of 2–acrylamido-2-methyl propane sulfonic acid homopolymer and its copolymer with N-vinyl pyrrolidone were used as capping agents to control the ZnO shapes and sizes. The surface charges, morphology, particle sizes and chemical structure of ZnO capped with PIL were studied as well as their antimicrobial activity. The prepared ZnO nanomaterial was used to prepare crosslinked 2–acrylamido-2-methyl propane sulfonic acid-co-acrylonitrile nanocomposites to apply as adsorbent for methylene blue dye from water as harmful organic pollutants. The ZnO composites achieved high adsorption removal rate for 3000 mg/L of MB from water during 20 min.
- Published
- 2017
48. Studies on Opuntia dilenii haw mediated multifunctional ZnFe 2 O 4 nanoparticles: Optical, magnetic and catalytic applications
- Author
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L. John Kennedy, M. Bououdina, K. Kombaiah, J. Judith Vijaya, R. Jothi Ramalingam, and Hamad A. Al-Lohedan
- Subjects
Materials science ,Analytical chemistry ,Nanoparticle ,02 engineering and technology ,Coercivity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Crystallinity ,Phase (matter) ,General Materials Science ,Crystallite ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Microwave - Abstract
The sustainable and eco friendly green synthesis report on the use of plant extract alternate to chemicals has been discussed. In this work, opuntia plant extract is used as a natural reagent to synthesize nanoparticles. Herein, we demonstrate two methods namely, conventional and microwave method for the synthesis of nanoparticles using plant extract, due to its easy handling and bio-compatibility. Both the methods were carried out under the same conditions to explore the comparison of the data. Various characterization techniques were used to determine the crystallinity, crystallite size, lattice parameter, morphology, elemental composition, band gap energy, emission, saturation magnetization, and coercivity of the as-synthesized nanoparticles. A brief discussion about the importance of using the plant extract as well as the importance of microwave heating were discussed and summarized. The phase identification was examined using XRD analysis, which showed the formation of single and pure phase without any post annealing in microwave heating method. The formation of pure phase ferrites is also confirmed by Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology of ZnFe 2 O 4 nanoparticles showed spherical shape and the size difference depends upon the method of synthesis. EDX analysis confirms the phase-purity of the as-synthesized nanoparticles. UV–Vis DRS of the as-obtained nanospheres exhibited the absorbance in the visible region. VSM analysis showed that the sample prepared by microwave technique exhibited better magnetic behaviour at room temperature than that of the ones prepared by the conventional heating method. The microwave heating technique produces nano-ferrites with high yield, low crystallite size, uniform morphology, and good absorption properties than the conventional heating method. Zinc ferrites were used in the catalytic reaction for the oxidation of glycerol into formic acid. The catalyst exhibit good catalytic performance and better selectivity of formic acid throughout the reaction. The plausible mechanism has been proposed.
- Published
- 2017
49. Deciphering the interaction of procaine with bovine serum albumin and elucidation of binding site: A multi spectroscopic and molecular docking study
- Author
-
Mohd. Sajid Ali and Hamad A. Al-Lohedan
- Subjects
Circular dichroism ,Stereochemistry ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Fluorescence spectroscopy ,Hydrophobic effect ,Procaine ,Materials Chemistry ,medicine ,Physical and Theoretical Chemistry ,Binding site ,Bovine serum albumin ,Spectroscopy ,biology ,Hydrogen bond ,Chemistry ,Cooperative binding ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Crystallography ,biology.protein ,0210 nano-technology ,medicine.drug - Abstract
The mechanism of interaction between anesthetic drug procaine with model serum protein bovine serum albumin (BSA) was seen by means of various spectroscopic and molecular docking methods. The spectroscopic techniques used in the study were UV visible, fluorescence quenching, 3-d fluorescence, circular dichroism (CD), and Forster resonance energy transfer (FRET). Formation of the ground state complex between procaine and BSA was evidenced from the UV–visible spectrophotometry. Due to the strong absorption of procaine at the excitation wavelength, inner filter effect was corrected for the fluorescence analyses. There was 1:1 cooperative binding between BSA and procaine which was taken place via static mechanism. Procaine was found to slightly induce the secondary structure of BSA by increasing its α-helical contents. Thermodynamic parameters revealed that hydrogen bonding and hydrophobic forces played important role in the binding. From the competitive binding measurements it was shown that the principal binding site for the procaine in BSA was site 1, located in the hydrophobic cavity of subdomain IIA. Both these experimental observations i.e., thermodynamic parameters analysis and site specific studies were supported by theoretical molecular docking analysis according to which procaine binds to the vicinity of His67, Glu100 via hydrogen bonding and Asn99, Pro96, Ser65, Glu6, His246, Glu243, Asp248, and Glu251 via hydrophobic interactions. The most favorable site of the procaine was located near the Sudlow's site 1.
- Published
- 2017
50. Salt-controlled self-healing nanogel composite embedded with epoxy as environmentally friendly organic coating
- Author
-
Hussin I. Al-Shafey, Mohamed F. Wahby, Hamad A. Al-Lohedan, Ashraf M. El-Saeed, and Ayman M. Atta
- Subjects
Materials science ,Composite number ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Coating ,mental disorders ,Composite material ,chemistry.chemical_classification ,Nanocomposite ,Surfaces and Interfaces ,General Chemistry ,Polymer ,Epoxy ,021001 nanoscience & nanotechnology ,Exfoliation joint ,0104 chemical sciences ,Surfaces, Coatings and Films ,Montmorillonite ,chemistry ,visual_art ,engineering ,visual_art.visual_art_medium ,0210 nano-technology ,Nanogel - Abstract
Smart nanogel capsules are attracting great attention to act as self-healing materials for polymers and epoxy coating and as anticorrosion materials. The present work aimed at incorporating nanogel among silicate layers of sodium montmorillonite (Na-MMT) to increase its dispersibility into an epoxy matrix so as to be used as self-healing nanocomposites. For this purpose, N-isopropyl acrylamide (NIPAm) as a salt-sensitive monomer was selected to prepare smart nanogels to disperse the Na-MMT layers. The chemical structure, surface morphology, particle size distribution, surface charge, and degree of exfoliation of Na-MMT with NIPAm nanogel were investigated. The ability of Na-MMT/NIPAm to modify the mechanical, surface, and self-healing characteristics of epoxy matrix was studied. The corrosion inhibition and self-healing mechanism were discussed in light of salt spray resistance of epoxy nanocomposites to protect steel from corrosive environments.
- Published
- 2017
Catalog
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