44 results on '"M.S. Jyothi"'
Search Results
2. Progress in Photocatalysis for Hydrogen Evolution and Environmental Remediation
- Author
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R. Shwetharani, M.S. Jyothi, M. Dinamani, and S. Radoor
- Published
- 2023
3. List of contributors
- Author
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Luma M. Ahmed, Chetna Ameta, Garima Ameta, Rakshit Ameta, Rameshwar Ameta, Suresh C. Ameta, Anca Armşelu, R. Geetha Balakrishna, Indu Bhati, Jayesh P. Bhatt, Priyanka Chundawat, null Dharmendra, Neha Godha, Meghavi Gupta, Chandan Hunsur Ravikumar, Abhilasha Jain, Monika Jangid, Kanchan K. Jat, Thaqeef M. Jawad, Priyanka Jhalora, M.S. Jyothi, Hamad H. Kadium, Seema Kothari, Neelam Kunwar, Kushnuma Parveen, Shwetharani R, Avinash K. Rai, Neetu Shorgar, Shubang Vyas, Yogeshwari Vyas, Inderjeet Yadav, and Hetal Zala
- Published
- 2023
4. Application of quantum dots in solar cells
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Shwetharani R, Chandan Hunsur Ravikumar, M.S. Jyothi, and R. Geetha Balakrishna
- Published
- 2023
5. Development of sustainable alternative materials for the construction of green buildings using agricultural residues: A review
- Author
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Sangmesh B., Nagraj Patil, Krishna Kumar Jaiswal, T.P. Gowrishankar, K. Karthik Selvakumar, M.S. Jyothi, R. Jyothilakshmi, and Santosh Kumar
- Subjects
General Materials Science ,Building and Construction ,Civil and Structural Engineering - Published
- 2023
6. Nonwoven fabric supported, chitosan membrane anchored with curcumin/TiO2 complex: Scaffolds for MRSA infected wound skin reconstruction
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M.S. Jyothi, Khantong Soontarapa, Rajendran Velmurugan, Rangappa S. Keri, and Roopesh Marulasiddeshwara
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0303 health sciences ,integumentary system ,Biomaterial ,02 engineering and technology ,General Medicine ,021001 nanoscience & nanotechnology ,Biochemistry ,In vitro ,Chitosan ,03 medical and health sciences ,chemistry.chemical_compound ,chemistry ,Structural Biology ,In vivo ,Curcumin ,Biophysics ,Viability assay ,0210 nano-technology ,Wound healing ,Drug carrier ,Molecular Biology ,030304 developmental biology - Abstract
Use of biomaterial scaffolds as drug carriers for infected wounds treatment is of wide scope. A series of curcumin/TiO2 complex loaded chitosan scaffolds are fabricated for the same. Synthesized wound dressing material is screened for their morphology, water absorption capacity; in vitro drug release patterns, in vitro antibacterial studies against gram +ve and a gram −ve bacteria, cell viability for 3T3-L1 cell lines as well as in vivo MRSA infected wound healing capability. Formation of curcumin/TiO2 complex was confirmed by X-ray diffraction studies, the anchoring pattern of them on the chitosan scaffold was analyzed by FESEM and EDS mapping. All membranes showed a better performance towards in vitro antibacterial and in vivo wound healing properties than the control ones in 14 days. The bacterial count on wound for a regular time period was measured and the scaffold with higher amount of curcumin in its complex is found to give the better performance, along with skin regeneration due to synergistic effect of curcumin and TiO2.
- Published
- 2020
7. Contributors
- Author
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Wesam Al Khateeb, Bahaa Al Trad, Mazhar S. Al Zoubi, Abdullah Alamin, Khalid M. Al-Batanyeh, Alaa A.A. Aljabali, Almuthanna K. Alkaraki, Adel Alrababaa, null Asiya SI, Nidhi Asthana, Preetam Bhardwaj, Ch. G. Chandaluri, Ramchander Chepyala, Naveen K. Dandu, Dilshat Rubia Dola, Ahmad El-Oqlah, Irene S. Fahim, R. Geetha Balakrishna, Andrews Nirmala Grace, Alka Gupta, Md Enamul Hoque, Emad I. Hussein, M.S. Jyothi, Moshiur Rahman Khan, Tausif Hasan Khan, Anitha C. Kumar, M.L.N. Madhu Mohan, N. Mahender Reddy, Riyadh Muhaidat, Kaushik Pal, Gangadhar Purohit, Janti Qar, Sabarish Radoor, Gubbala V. Ramesh, Abu Bakkar Siddique Samrat, Zayed Bin Zakir Shawon, R. Shwetharani, Kiran Kumar Tadi, Murtaza M. Tambuwala, and Samarth Trivedi
- Published
- 2022
8. Switchable photovoltaic effect in solar cells: Architecture, features, and future scope
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M.S. Jyothi, R. Shwetharani, Sabarish Radoor, and R. Geetha Balakrishna
- Published
- 2022
9. Choloromethane and bromomethane adsorption studies on hex-star phosphorene nanoribbon – A DFT insight
- Author
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M.S. Jyothi, V. Nagarajan, and R. Chandiramouli
- Subjects
Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2023
10. Aniline and chlorobenzene interaction studies on θ-arsenene nanosheet - a first-principles study
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M.S. Jyothi, V. Nagarajan, and R. Chandiramouli
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Inorganic Chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry - Published
- 2022
11. Magnetic Nanoparticles Impregnated, Cross-Linked, Porous Chitosan Microspheres for Efficient Adsorption of Methylene Blue from Pharmaceutical Waste Water
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M.S. Jyothi, V. Jagadeesha Angadi, T. V. Kanakalakshmi, Khantong Soontarapa, Mahesh Padaki, and Balakrishna R. Geetha
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Langmuir ,Environmental Engineering ,Materials science ,Polymers and Plastics ,Cationic polymerization ,Nanoparticle ,02 engineering and technology ,021001 nanoscience & nanotechnology ,chemistry.chemical_compound ,Adsorption ,020401 chemical engineering ,chemistry ,Chemical engineering ,Desorption ,Materials Chemistry ,Magnetic nanoparticles ,Freundlich equation ,0204 chemical engineering ,0210 nano-technology ,Methylene blue - Abstract
The study demonstrates the preparation of MnFe2O4 impregnated chitosan-microspheres (CMMS) as adsorbents for efficient removal of cationic thiazine dye, methylene blue. A facile approach with great economic and technical advantages to obtain highly crystalline manganese ferrite nanoparticles by solution combustion method is accounted. CMMS were characterized and evaluated for MB adsorption using linear forms of Freundlich and Langmuir adsorption isotherms, pseudo-first order, pseudo-second order and Elovich kinetic models. Application of CMMS to pharmaceutical waste, desorption of MB and reusability of CMMS are reported. Significantly, MB concentration in treated real sample was reduced by ~ 18 times to that of initial concentration.
- Published
- 2019
12. Recent advances in non-metals-doped TiO2 nanostructured photocatalysts for visible-light driven hydrogen production, CO2 reduction and air purification
- Author
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Nagaraju Ganganagappa, Anjanapura V. Raghu, Shivaraj B. Patil, M.S. Jyothi, Kakarla Raghava Reddy, and Patil S. Basavarajappa
- Subjects
Materials science ,Hydrogen ,Renewable Energy, Sustainability and the Environment ,Band gap ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Fuel Technology ,chemistry ,Photocatalysis ,Water splitting ,0210 nano-technology ,Photocatalytic water splitting ,Visible spectrum ,Hydrogen production - Abstract
The generation of hydrogen and oxygen from the photocatalytic water splitting reaction under visible light is a promisingly renewable and clean source for H2 fuel. The transition metal oxide semiconductors (e.g. TiO2, WO3, ZnO, and ZrO2) are have been widely used as photocatalysts for the hydrogen generation. Because of safety, low cost, chemical inertness, photostability and other characteristics (bandgap, corrosion resistance, thermal and environmental stability), TiO2 is considered as a most potential catalyst of the semiconductors being investigated and developed. However, the extensive applications of TiO2 are hampered by its inability to exploit the solar energy of visible region. Other demerits are lesser absorbance under visible light, and recombination of photogenerated electron-hole pairs. In this review, we focus on the all the possible reactions taking place at the catalyst during photo-induced H2 from water splitting reaction, which is green and promising technology. Various parameter affecting the photocatalytic water splitting reactions are also studied. Predominantly, this review is focussed on bandgap engineering of TiO2 such as the upward shift of valence band and downward shift of conduction bands by doping process to extend its light absorption property into the visible region. Furthermore, the recent advances in this direction including various new strategies of synthesis, multiple doping, hetero-junction, functionalization, perspective and future opportunities of non-metals-doped TiO2-based nanostructured photocatalysts for various photocatalytic applications such as efficient hydrogen production, air purification and CO2 reduction to valuable chemicals have been discussed.
- Published
- 2019
13. Supplementing multi-functional groups to polysulfone membranes using Azadirachta indica leaves powder for effective and highly selective acid recovery
- Author
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M.S. Jyothi, Khantong Soontarapa, Mahesh Padaki, R. Geetha Balakrishna, Juin-Yih Lai, and Sudesh Yadav
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Environmental Engineering ,Polymers ,Health, Toxicology and Mutagenesis ,Diffusion ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Industrial waste ,Ion ,chemistry.chemical_compound ,Cation-exchange capacity ,Environmental Chemistry ,Recycling ,Ferrous Compounds ,Sulfones ,Polysulfone ,Waste Management and Disposal ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,Azadirachta ,biology ,Hydrogen bond ,Chemistry ,Membranes, Artificial ,biology.organism_classification ,Pollution ,Plant Leaves ,Membrane ,Hydrochloric Acid ,Plant Preparations ,Powders ,Water Pollutants, Chemical ,Nuclear chemistry - Abstract
Moderate and eco-pleasing ion-exchange trade membranes are in need to recover acid from industrial waste. Present study is focused on incorporation of plant waste (Azadirachta indica, neem leaves powder (NP)) of different composition as filler to polysulfone (PSf) membrane matrix to achieve acid recovery. Membranes were characterized, their chemical, mechanical and thermal stabilities and effectiveness in acid recovery via diffusion has been inspected. Multi-functional groups (−COOH, -NH2, −OH, -OAc, -C = O) present in different components of NP contributes in their own means in H+ ion transportation through membrane in acid recovery. They assisted formation of hydrogen bond and provided channels for ion permeation, and facilitated selective transportation of H+ ion over Fe2+ ions and explained mechanism is in accordance with Grotthuss-type and vehicle mechanism. Membrane with 15% of NP showed better performance in terms of ion exchange capacity (IEC) and acid recovery, at optimum concentration of NP, composite the membrane showed highest IEC values of 3.9771 mmol/g, UH+ value of ≈46.499 × 10−3 m/h and greater separation factor ≈154, which is higher than commercially available DF-120 membrane. An original thought of utilizing NP in membrane matrix opens up promising opportunities for extremely straightforward, easy, cost-effective and greener methods of recovery acid.
- Published
- 2019
14. 'Environmental friendly and cost effective caramel for congo red removal, high flux, and fouling resistance of polysulfone membranes'
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Khantong Soontarapa, M.S. Jyothi, R. Geetha Balakrishna, and C. Lavanya
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Fouling ,Chemistry ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Caramelization ,Analytical Chemistry ,Congo red ,Biofouling ,chemistry.chemical_compound ,Membrane ,020401 chemical engineering ,Chemical engineering ,Water treatment ,Polysulfone ,0204 chemical engineering ,Phase inversion (chemistry) ,0210 nano-technology - Abstract
This study demonstrates the caramel as a hydrophilic additive material towards improving the performance and antifouling properties of Polysulfone (PSF) membranes. It is found that the functional molecules that formed upon the caramelization of sugar enhance the performance of the PSF membranes in terms of their permeability as well as the hydrophilicity. Thus, the PSF-based flat sheet membranes were prepared by phase inversion technique with different additional amounts of caramel (i.e., 50 mg, 150 mg and 250 mg). The prepared membranes were characterized and their performance was evaluated by pure water flux, water uptake and contact angle measurements. Studies on the rejection and fouling properties of membranes in water treatment were carried out using Bovine Serum Albumin (BSA). The modified membranes showed a significantly enhanced flux of ∼350 L/m2 h and the rejection of BSA was found to be 90%. It was also found that the antifouling capacity of the PSF membranes enhanced with caramel modification. Congo red removal using PSF-Caramel membrane was observed to be very effective in acidic conditions and the dye was able to be successfully recovered using ethanol. The membranes were reused for several times, which showed a consistent performance in flux and rejection of Congo red. Overall, the caramel modified membranes can open up new possibilities in enhancing the thermal, mechanical, hydrophilicity, water flux and antifouling properties of PSF membranes.
- Published
- 2019
15. Tetrahydrofuran and 2-methyltetrahydrofuran adsorption studies on violet phosphorene nanosheets based on first-principles studies
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M.S. Jyothi, V. Nagarajan, and R. Chandiramouli
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Materials Chemistry ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Spectroscopy ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2022
16. Chemisorption of atrazine and diuron molecules on γ-arsenene nanosheet - a first-principles study
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M.S. Jyothi, V. Nagarajan, and R. Chandiramouli
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General Physics and Astronomy ,Physical and Theoretical Chemistry - Published
- 2022
17. Adsorption studies of 2,3-butanedione and acetic acid on ζ-phosphorene sheets based on the first-principles study
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M.S. Jyothi, V. Nagarajan, and R. Chandiramouli
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Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2022
18. Exploration of graphene oxide nanoribbons as excellent electron conducting network for third generation solar cells
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J. Kusuma, M.S. Jyothi, H.R. Chandan, Siddappa A. Patil, R. Shwetharani, and R. Geetha Balakrishna
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Materials science ,Renewable Energy, Sustainability and the Environment ,Graphene ,business.industry ,Energy conversion efficiency ,Oxide ,02 engineering and technology ,Electron ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Electron transport chain ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Anode ,chemistry.chemical_compound ,chemistry ,Quantum dot ,law ,Optoelectronics ,0210 nano-technology ,business - Abstract
The future of third generation Quantum dot sensitized solar cells (QDSSCs) can be optimistic if concerns of charge recombination and stability of cells can be worked upon. In this work, we report the role of Graphene materials in its different dimension in overcoming recombination and enhancing power conversion efficiency (PCE). Composite of Graphene oxide nanoribbons (GNRs) synthesized by oxidative unzipping of multi walled carbon nanotubes (MWCNTs) was used as an effective electron transport layer with TiO2 as photo anode in QDSSCs. The best performing TiO2-GNR showed a significant enhancement in PCE of 3.7% for CdS based quantum dots, apart from increased efficiency reported earlier. Investigation of design of anode material reveals that the enhanced surface area and active sites of partially conducting GNRs facilitated uniform deposition of Titania particles (TiO2) with less aggregation, excellent mobility, presence of organic functional group for anchor of TiO2, its 1D quasi structure add to enhanced electron transport (less resistance).
- Published
- 2018
19. Effective recovery of acids from egg waste incorporated PSf membranes: A step towards sustainable development
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M.S. Jyothi, Geetha R. Balakrishna, and Sudesh Yadav
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chemistry.chemical_classification ,Hydrogen ,Hydrogen bond ,chemistry.chemical_element ,Filtration and Separation ,02 engineering and technology ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Amino acid ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,General Materials Science ,Thermal stability ,Chemical stability ,Polysulfone ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
A required progress in developing effective membranes for diffusion dialysis provides a platform to explore novel hybrid membranes for acid recovery. This novel study investigated a feasibility of egg shell membrane powder in enhancing proton permeability of polysulfone membrane, thereby promoting a sustainable development in acid recovery. Hybrid membranes with different concentration loading of egg shell membrane to polysulfone were fabricated, characterized and analyzed in terms of water uptake, ion exchange capacity, chemical stability, thermal stability and mechanical stability and the viability towards effective acid recovery. Results revealed that, prepared EP membranes showed almost 5.55 folds greater proton permeability and very high separation factor than most commercially available DF- 120 membrane. Enhancement in performance and acid recovery in the whole work is credited to presence of amino acids groups in egg shell membrane with enormous amount of hydrogen bond donar and acceptor sites which helps in hydrogen bond formation, and occurrence of π- π interactions with polysulfone forming channels to effectively permeate hydrogen ions. Also, these structural interactions remarkably increased the membrane stiffness compared to pristine PSf membrane and showed better mechanical stability. The strategy behind this work is promising for developing high performance, sustainable product for rapid acid recovery which could be examined in detail to apply for industrial spent acid recovery.
- Published
- 2018
20. La activated high surface area titania float for the adsorption of Pb(<scp>ii</scp>) from aqueous media
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R. Shwetharani, A Poojashree, Geetha R. Balakrishna, and M.S. Jyothi
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Dopant ,Chemistry ,Inorganic chemistry ,Doping ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,law.invention ,Adsorption ,X-ray photoelectron spectroscopy ,law ,Materials Chemistry ,Surface roughness ,Crystallite ,Particle size ,0210 nano-technology ,Atomic absorption spectroscopy - Abstract
Currently, the world faces alarming challenges of heavy metal contamination, which are hazardous to humans and the environment because of their toxicity even in trace concentrations. Lead is one of the harmful heavy metal contaminants and has poisonous effects on human health. The present research investigation describes the adsorption of toxic Pb(II) on an immobilized adsorbent with a highly smaller crystallite size along with enhanced surface area and pore volume of La doped TiO2 synthesized from a simple co-precipitation method. Induction of dopant La3+ was confirmed by XPS with a smaller particle size of 25 nm as compared to TiO2 of 80 nm. The La doped TiO2 shows an enhanced surface area of 97.246 m2 g−1 compared to TiO2 of 17.2 m2 g−1 due to the introduction of oxygen vacancies leading to increased surface roughness and thus shows significant improvement in the adsorption of Pb(II) in comparison with TiO2 at basic pH due to the negative charge on La doped TiO2. A suitable optimized pH was examined and the Pb(II) adsorption study was measured using atomic absorption spectroscopy.
- Published
- 2018
21. Adsorption behaviour of sulfisoxazole molecules on tricycle arsenene nanoribbon - a first-principles study
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R. Chandiramouli, V. Nagarajan, and M.S. Jyothi
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Materials science ,Band gap ,Sulfisoxazole ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Crystallography ,Adsorption ,Chemisorption ,Atom ,Materials Chemistry ,Density of states ,Density functional theory ,Physical and Theoretical Chemistry ,Electronic band structure ,Spectroscopy - Abstract
The density functional theory framework is used to study geometry and electronic properties of pristine tricycle arsenene nanoribbon (T-AsNR) and Ga substituted T-AsNR. The stable geometry of both T-AsNR is ensured based on the formation energies. The obtained formation energies for T-AsNR and Ga-substituted T-AsNR are −4.462 and −4.512 eV/atom, respectively. Also, the band gap is calculated to be 0.635 and 0.212 eV, respectively for pristine and Ga substituted T-AsNR, which are semiconductors. Furthermore, T-AsNR is used as a base substrate to adsorb sulfisoxazole in the aqueous medium. Moreover, the adsorption of sulfisoxazole on both T-AsNR possesses chemisorption. Besides, the adsorption energy at the valley site of T-AsNR and Ga-substituted T-AsNR are −6.313 eV and −6.346 eV. The average energy gap variation for Ga-substituted T-AsNR was highest at the top site and is about 174.06%, whereas the pristine one showed 6.93 %. The change in the electronic properties of T-AsNR is observed with regard to band structure, electron density, and density of states spectrum. Thus, the outcome suggests that T-AsNR is a prominent adsorbing medium of sulfisoxazole in contaminated water.
- Published
- 2021
22. Interaction studies of benzene and phenol on novel 4–8 arsenene nanotubes – A DFT insight
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M.S. Jyothi, R. Chandiramouli, and V. Nagarajan
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Electron density ,Band gap ,Condensed Matter Physics ,Photochemistry ,Biochemistry ,chemistry.chemical_compound ,Adsorption ,chemistry ,Density of states ,Phenol ,Molecule ,Physical and Theoretical Chemistry ,Benzene ,Electronic band structure - Abstract
The adsorption properties of benzene and phenol molecules on 4–8 arsenene nanotubes (4–8 AsNT) are investigated based on the DFT framework. The structural stability is confirmed with a formation energy of 4–8 AsNT, which has −3.696 eV/atom. The band structure and density of states spectrum reveal that 4–8 AsNT exhibits a band gap of 0.504 eV. The adsorption energy for the complex structure is noticed to be in the scope of −0.253 eV to −0.602 eV, which confirms that the benzene and phenol molecules are physisorbed on 4–8 AsNT. The charge transfer and electron density difference support the change in the electronic attributes of 4–8 AsNT due to the adsorption of benzene and phenol molecules on 4–8 AsNT. The chemi-resistive nature is observed upon adsorption of benzene/phenol on 4–8 AsNT. Thus, the study reveals that 4–8 AsNT can be employed as a chemical nanosensor for benzene and phenol detection.
- Published
- 2021
23. Interaction studies of dichlobenil and isoproturon on square-octagon phosphorene nanotube based on DFT frame work
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R. Chandiramouli, V. Nagarajan, and M.S. Jyothi
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Materials science ,Band gap ,Stacking ,General Physics and Astronomy ,Aromaticity ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Phosphorene ,chemistry.chemical_compound ,Adsorption ,chemistry ,Chemisorption ,Chemical physics ,Density of states ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Square-octagon phosphorene nanotubes (so-PNT) have aroused attention among researchers owing to their interaction with pesticide molecules. In the current report, the adsorption features of dichlobenil, and isoproturon on so-PNT at three different orientations (inner, octa, and tetra vacancy of so-PNT) are explored with the framework of density functional theory. Moreover, the adsorption features are conversed in terms of adsorption energy, band gap variation, charge transfer, and band structure maps. Besides, the adsorption aspects of dichlobenil and isoproturon are also demonstrated with regard to the density of states spectrum. The electron density difference of so-PNT articulates the adsorption features of target molecules. In addition, the outcome of the proposed study enunciates the chemisorption nature of dichlobenil, and isoproturon molecules on so-PNT. Thus, so-PNT can be considered as an efficient material for the removal of dichlobenil, and isoproturon molecules. Furthermore, the chemisorption process is attributed to the presence of polar groups and the aromatic rings in the targets system offering π- π interactions and stacking along with electron-donor–acceptor interactions between target contaminants and so-PNT.
- Published
- 2021
24. Favorable influence of mPIAM on PSf blend membranes for ion rejection
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Khantong Soontarapa, Mahesh Padaki, R. Geetha Balakrishna, M.S. Jyothi, and Arun M. Isloor
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Metal ions in aqueous solution ,Maleic anhydride ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Biochemistry ,chemistry.chemical_compound ,Membrane ,020401 chemical engineering ,chemistry ,Chemical engineering ,Polymer chemistry ,General Materials Science ,Surface charge ,Polysulfone ,Nanofiltration ,0204 chemical engineering ,Physical and Theoretical Chemistry ,Phase inversion (chemistry) ,0210 nano-technology ,Sulfanilic acid - Abstract
The study reports the use of a novel membrane for heavy metal removal and salt rejection. Poly isobutylene alt maleic anhydride (PIAM) modified by sulfanilic acid is blended with polysulfone (PSf) in different concentrations. This induces surface charge and hydrophillicity in the otherwise hydrophobic PSf membranes. The so modified polymers and their blends are characterized by spectroscopic and microscopic techniques. Blend membranes show drastically enhanced performance with respect to water flux, water uptake and ion exchange capacity. SEM micrographs indicate the hydrophilic domains, –SO 3 H groups in the polymer to have formed cavities during phase inversion process, thus enhancing permeability. 100% rejection of PEG 2000 and 59% of NaCl rejection substantiated the nature of the membrane to be nanofiltration (NF) type. The prepared membranes were further evaluated for Cr (VI) removal, with removal efficiency reaching above 92%. The electronic coupling that occurs between SO 3 H − and Na + and the electrostatic interaction between metal ions and the charge on membrane facilitates NaCl and Cr (VI) rejection respectively. The study gains significance in use of such modified PIAM as blend material with any other polymer to enhance the native properties of the blend membrane.
- Published
- 2017
25. Novel modified poly vinyl chloride blend membranes for removal of heavy metals from mixed ion feed sample
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Vignesh Nayak, R. Geetha Balakrishna, Mahesh Padaki, M.S. Jyothi, Sébastien Déon, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,Metal ions in aqueous solution ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Contact angle ,chemistry.chemical_compound ,Chromium ,Polymer chemistry ,[CHIM]Chemical Sciences ,Environmental Chemistry ,Polysulfone ,Waste Management and Disposal ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Benzoic acid ,chemistry.chemical_classification ,Chemistry ,Chemical modification ,Polymer ,021001 nanoscience & nanotechnology ,Pollution ,6. Clean water ,3. Good health ,Membrane ,Chemical engineering ,0210 nano-technology - Abstract
Herein, an attempt has been made to prepare a novel membrane with good efficiency for removal of heavy metal ions namely lead (Pb), cadmium (Cd) and chromium (Cr). 4-amino benzoic acid (ABA) was covalently grafted onto the poly vinyl chloride (PVC) backbone by CN bond to enhance the hydrophilicity. 1H NMR and ATR-IR spectroscopy analysis confirmed the chemical modification of PVC. Further the modified polymer was blended in different compositions with polysulfone (PSf) for optimization. Morphological changes that occurred in blend membranes, due to the incorporation of modified PVC was studied by AFM and SEM techniques. The effect on hydrophilicity and performance of blends owing to incorporation of modified PVC was evaluated by water uptake, contact angle and flux studies. The density of functional groups in blends was analyzed by its ion-exchange capacity. Batch wise filtration of metal ions was carried out and the effect of pressure, feed pH and interference of ions was thoroughly investigated. Essentially, 100% rejection was obtained for all the metal ions in acidic pH with a productivity of 2.56l/m2h. The results were correlated with the results of commercially available NF 270 membrane under the same operating conditions.
- Published
- 2017
26. Sunlight active PSf/TiO 2 hybrid membrane for elimination of chromium
- Author
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Vignesh Nayak, M.S. Jyothi, Mahesh Padaki, and R. Geetha Balakrishna
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General Chemical Engineering ,Radical ,Inorganic chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Metal ,chemistry.chemical_compound ,Chromium ,Membrane ,chemistry ,law ,visual_art ,Photocatalysis ,visual_art.visual_art_medium ,Polysulfone ,0210 nano-technology ,Bifunctional ,Filtration - Abstract
The report aims to develop and use sunlight-active catalyst-membrane to reduce toxic Cr (VI) to less toxic Cr (III) and to reject Cr (III) from Cr contaminated water. Polysulfone and TiO2 nanoparticles were hybridized, to induce a bifunctional efficacy of metal ion reduction and separation. Reduction of Cr (VI) results in the formation of Cr (III), which is larger in size facilitating rejection. Hybrid membranes possess superior hydrophilicity and permeability with an added advantage of enhanced metal ion reduction and rejection. Photoreduction of Cr (VI) requires the presence of acid to avoid accumulation of holes and hydroxyl radicals in the reaction medium. Cr (III) solution obtained after photoreduction was subjected to direct filtration without any pretreatment, so as to obtain complete Cr-free water.
- Published
- 2017
27. Non-metal (Oxygen, Sulphur, Nitrogen, Boron and Phosphorus)-Doped Metal Oxide Hybrid Nanostructures as Highly Efficient Photocatalysts for Water Treatment and Hydrogen Generation
- Author
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M.S. Jyothi, Kakarla Raghava Reddy, S. Naveen, Vignesh Nayak, and Anjanapura V. Raghu
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Materials science ,Oxide ,chemistry.chemical_element ,Environmental pollution ,Nitrogen ,Metal ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,Photocatalysis ,Water treatment ,Boron ,Hydrogen production - Abstract
Inorganic metal oxide semiconductor-based photocatalyst plays key role in the photocatalytic process for applications such as environmental pollution (air and water) and hydrogen generation, due to their physico-chemical and photocatalytic properties. However, they are only active under ultraviolet irradiation, and it is a major drawback of oxide-based photocatalysts. The designing of visible-light-driven photocatalysts based on metal oxides is very important for the highly efficient photocatalytic process.
- Published
- 2019
28. Membranes for dehydration of alcohols via pervaporation
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Tejraj M. Aminabhavi, Raghavendra V. Kulkarni, Mallikarjuna N. Nadagouda, D.P. Suhas, Kakarla Raghava Reddy, S. Naveen, Nagaraj P. Shetti, M.S. Jyothi, Khantong Soontarapa, and Anjanapura V. Raghu
- Subjects
Environmental Engineering ,Polymers ,0208 environmental biotechnology ,Synthetic membrane ,Alcohol ,02 engineering and technology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,law ,medicine ,Organic chemistry ,Humans ,Dehydration ,Waste Management and Disposal ,Distillation ,0105 earth and related environmental sciences ,Ethanol ,Membranes, Artificial ,General Medicine ,medicine.disease ,020801 environmental engineering ,Membrane ,chemistry ,Pervaporation ,Polymeric membrane - Abstract
Alcohols are the essential chemicals used in a variety of pharmaceutical and chemical industries. The extreme purity of alcohols in many of such industrial applications is essential. Though distillation is one of the methods used conventionally to purify alcohols, the method consumes more energy and requires carcinogenic entertainers, making the process environmentally toxic. Alternatively, efforts have been made to focus research efforts on alcohol dehydration by the pervaporation (PV) separation technique using polymeric membranes. The present review is focused on alcohol dehydration using PV separation technique, which is the most efficient and benign method of purifying alcohols that are required in fine chemicals synthesis and developing pharmaceutical formulations. This review will discuss about the latest developments in the area of PV technique used in alcohol dehydration using a variety of novel membranes.
- Published
- 2018
29. Novel hydrothermal method for effective doping of N and F into nano Titania for both, energy and environmental applications
- Author
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M.S. Jyothi, Geetha R. Balakrishna, R. Shwetharani, and P. D’Souza Laveena
- Subjects
Materials science ,Open-circuit voltage ,Band gap ,Mechanical Engineering ,Binding energy ,Doping ,Inorganic chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Hydrothermal circulation ,0104 chemical sciences ,Chemical engineering ,Mechanics of Materials ,Photocatalysis ,General Materials Science ,Charge carrier ,0210 nano-technology ,Visible spectrum - Abstract
A novel and an efficient hydrothermal method for the preparation of an effective doped titania photocatalyst is reported. The crystal phase, binding energy, elemental composition, morphology, optical and electronic structure analyses were done by various techniques. The doped titania proved as an efficient electrode material and photocatalyst for solar cells and water treatment respectively. The photocatalyst is able to degrade the most potent mutagen ethidium bromide under sunlight with an enhancement of 1.6 times over its undoped analogue. As photo-anode material, showed an improved open circuit potential and fill factor. The created electron states in the doped sample act as charge carrier traps suppressing recombination which later detraps the same to the surface of the catalyst causing enhanced interfacial charge transfer. Surface acidity caused by F induction and lowered band gap energy that can respond to visible light facilitates improved energy harvesting and energy transfer leading to better photo activity.
- Published
- 2016
30. Synthesis and characterization of novel sulfanilic acid–polyvinyl chloride–polysulfone blend membranes for metal ion rejection
- Author
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Arun M. Isloor, Mahesh Padaki, M.S. Jyothi, R. Geetha Balakrishna, and Vignesh Nayak
- Subjects
chemistry.chemical_classification ,Chromatography ,biology ,General Chemical Engineering ,Metal ions in aqueous solution ,02 engineering and technology ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,Contact angle ,chemistry.chemical_compound ,Polyvinyl chloride ,Membrane ,020401 chemical engineering ,chemistry ,biology.protein ,Polysulfone ,0204 chemical engineering ,Bovine serum albumin ,0210 nano-technology ,Nuclear chemistry ,Sulfanilic acid - Abstract
Near-complete removal of heavy metals, namely Cd(II), Cr(VI) and Pb(II), has been attempted by a membrane purification process using a blend of modified polyvinyl chloride (PVC) and polysulfone (PSf), prepared by the diffusion induced phase separation (DIPS) method. The prepared novel material was characterized by NMR, ATR-IR spectroscopy and DSC. The sulphonyl groups incorporated into PVC enhance the hydrophilicity and are substantiated by water uptake, contact angle (CA) and flux studies. The obtained properties of the blend membrane like increased surface roughness and porosity are observed from AFM and SEM analysis. An enhanced rejection of ∼95% which is about 1.15, 1.41 and 1.37 times better than the commercially available NF 270 membrane was observed, for Cd(II), Cr(VI) and Pb(II) respectively. The work was further extended to study the antifouling property and the interference of other existing metal ions on the performance. An improved antifouling property with 98.5% rejection for bovine serum albumin (BSA) and a 75.6% flux recovery ratio (FRR) was achieved. The study gains significance in exploring the incorporation of sulphonyl groups in to polymers, to enhance membrane performance.
- Published
- 2016
31. Aminated polysulfone/TiO2 composite membranes for an effective removal of Cr(VI)
- Author
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Vignesh Nayak, R. Geetha Balakrishna, Khantong Soontarapa, Mahesh Padaki, and M.S. Jyothi
- Subjects
chemistry.chemical_classification ,Anatase ,Materials science ,General Chemical Engineering ,Ultrafiltration ,Chemical modification ,02 engineering and technology ,General Chemistry ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Separation process ,Contact angle ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Polymer chemistry ,Environmental Chemistry ,Polysulfone ,0210 nano-technology - Abstract
A hydrophobic, ultrafiltration (UF), polysulfone (PSf) was reformed into a hydrophilic polymer by introducing amine groups via chemical modification. The amination was achieved by nitration to PSf followed by reduction using Na2S2O4. The modified polymer (aPSf) was characterized by NMR spectroscopy, ATR-IR, DSC and TGA. aPSf was further made into a composite membrane by using nano fillers. The prepared membranes were characterized by XRD, SEM and ion exchange capacity (IEC). The transformation in phase of TiO2 from anatase to rutile due to excess internal strain caused by amine groups was revealed by XRD patterns. Water uptake (WU), contact angle (CA) and pure water flux (PWF) were analyzed to study the hydrophilicity and performance of the membranes. These membranes were further considered for a novel approach of chromium removal by rejection/separation process. Essentially 100% separation was achieved depending on the surface charge properties of membrane, dosage of nano fillers, pH and interference of counter ions on rejection process.
- Published
- 2016
32. Investigation on adsorption properties of HCN and ClCN blood agents on θ–phosphorene nanosheets – A first–principles insight
- Author
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R. Chandiramouli, M.S. Jyothi, and V. Nagarajan
- Subjects
010304 chemical physics ,Band gap ,Chemistry ,General Physics and Astronomy ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Phosphorene ,chemistry.chemical_compound ,Adsorption ,Chemical physics ,0103 physical sciences ,Density of states ,Molecule ,Density functional theory ,Physical and Theoretical Chemistry ,Electronic band structure ,Nanosheet - Abstract
We investigated the electronic features and structural firmness of θ–phosphorene nanosheet (TPNS) based on density functional theory. The formation energy endorses the structural firmness of TPNS. The semiconducting nature of TPNS with an energy band gap of 1.326 eV supports its use as a base substrate to adsorb toxic blood agents, such as HCN and ClCN. The adsorption characteristics of HCN and ClCN were established using adsorption energy, charge transfer, and deviation in band gap of TPNS. Also, the change in the electronic properties of TPNS upon adsorption of HCN and ClCN has conversed with regard to band structure, density of states spectrum, and electron density. The overall findings suggest the use of θ–phosphorene nanosheets as a sensing medium for toxic HCN and ClCN molecules.
- Published
- 2020
33. Benzyl alcohol and 2-methyldecalin vapor adsorption studies on β-bismuthene sheets – A DFT outlook
- Author
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M.S. Jyothi, V. Nagarajan, and R. Chandiramouli
- Subjects
chemistry.chemical_classification ,010304 chemical physics ,Base (chemistry) ,Inorganic chemistry ,General Physics and Astronomy ,Substrate (chemistry) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Benzyl alcohol ,Desorption ,0103 physical sciences ,Density of states ,Molecule ,Physical and Theoretical Chemistry ,0210 nano-technology ,Nanosheet - Abstract
In the present research, β-bismuthene nanosheet (β-BiNS) is used as a base substrate to adsorb two volatile organic vapors evolved from sewer headspace, namely, benzyl alcohol (BA), and 2-methyldecalin (MD). Initially, the structural firmness of β-BiNS is established using cohesive formation energy and observed to be stable. The surface adsorption of BA and MD molecules on β-BiNS are explored with regard to the density of states, energy gap variation, adsorption energy, and charge transfer. Besides, β-BiNS exhibits chemi-resistive behavior upon adsorption and desorption of BA and MD vapors, which indicates its use as chemosensor towards toxic vapors evolved from sewer headspace.
- Published
- 2020
34. Review on recent advances of core-shell structured lead halide perovskites quantum dots
- Author
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Vignesh Nayak, R. Geetha Balakrishna, R. Shwetharani, and M.S. Jyothi
- Subjects
Brightness ,Photoluminescence ,Materials science ,Mechanical Engineering ,Metals and Alloys ,Halide ,Quantum yield ,Nanotechnology ,02 engineering and technology ,Luminescence quantum yield ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Core shell ,Lead (geology) ,Mechanics of Materials ,Quantum dot ,Materials Chemistry ,0210 nano-technology - Abstract
Lead halide perovskites have shown great potential in photovoltaic and optoelectronic devices due to their high brightness, defect tolerance, tunable emission wavelength, high color purity and near-unity luminescence quantum yield. Conversely, lead halide perovskites (LHP) show poor stability, which received strong criticism despite other promising characteristics. The poor stability attracted much research resulting in various modifications to enhance the stability and photoluminescence quantum yield (PLQY). The review outlines the basic structural and optical properties along with the conventional method of LHP synthesis and its drawbacks. Simultaneously discusses about factors responsible for instability like crystal structure, moisture, solvent, light and temperature. The review exclusively focuses on the recent research on core-shell LHP modification strategy to improve the stability and PLQY and its application in LED devices.
- Published
- 2020
35. 4-aminophenyl sulfone (APS) as novel monomer in fabricating paper based TFC composite for forward osmosis: Selective layer optimization
- Author
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Vignesh Nayak, Sergey Kaloshkin, Mahesh Padaki, M.S. Jyothi, V.Yu. Zadorozhnyy, and R. Geetha Balakrishna
- Subjects
Materials science ,Process Chemistry and Technology ,Forward osmosis ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Interfacial polymerization ,Selective surface ,chemistry.chemical_compound ,Membrane ,Monomer ,chemistry ,Chemical engineering ,Polymerization ,Polyamide ,Chemical Engineering (miscellaneous) ,0210 nano-technology ,Waste Management and Disposal ,Layer (electronics) ,0105 earth and related environmental sciences - Abstract
The potential of filter paper as a substrate material and 4-aminophenyl sulfone (APS) as a novel monomer for TFC fabrication is explored for the first time. A novel polyamide selective layer was developed using APS and trimesoyl chloride by interfacial polymerization, whereas the control TFC was prepared by replacing APS with m-phenylenediamine. Formation of the interfacial selective layer was verified by ATR-IR spectra and the stability of the selective surface coatings was discussed by investigating the monomer interaction. Surprisingly, after polymerization, interconnected, cross-linked structure of two monomers was observed. Desalination studies were carried out in FO mode and PRO mode using NH4HCO3 as a draw solution. Maximum of 90% and 95% rejection was obtained for NaCl and Na2SO4 salts with a flux of 2.51 and 2.17 LMH respectively. The separation efficiency of the prepared TFC membrane was compared against the likes of a commercial TFC membrane under the same conditions.
- Published
- 2020
36. Elimination of an Endocrine Disruptive Chemical by PSf/TiO2 hybrid Membranes via Membrane Rejection and Photocatalytic Oxidation
- Author
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R. Geetha Balakrishna, R. Shwetharani, V. S. Babu, Laveena P. D’Souza, M.S. Jyothi, and Mahesh Padaki
- Subjects
Contact angle ,chemistry.chemical_compound ,Anatase ,Membrane ,Materials science ,chemistry ,Chemical engineering ,Photocatalysis ,Polysulfone ,Crystallite ,Oxybenzone ,Bifunctional - Abstract
This study reports removal of oxybenzone from TiO2 nanoparticles and those incorporated mixed matrix membrane. Polysulfone and TiO2 nanoparticles mixed matrix membrane were prepared by Diffusion Induced Phase Separation (DIPS) method. The TiO2 nanoparticles and membranes were characterized by XRD, SEM, TEM, Raman spectroscopy and FESEM techniques; analysis depicts 100% anatase with spherical crystallite size averaging around 17 nm. The mixed matrix membranes were used for bifunctional application, physical separation and organic degradation. The membranes were subjected to pure water flux and contact angle measurements, the influence of TiO2 were to increase the hydrophilicity of the membrane, the performance of the membrane in physical separation showed prominent results by removing oxybenzone up to 95% where as in organic degradation membrane showed 80% of degradation. The efficiency of the membrane in degradation was more prominent as compared to bare TiO2 nanoparticles. The TiO2 nanoparticles show around 70% of degradation, whereas, the bifunctionality of the membranes showed more prominence in removal of complete oxybenzone.
- Published
- 2017
37. Synthesis and design of PSf/TiO2 composite membranes for reduction of chromium (VI): Stability and reuse of the product and the process
- Author
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Mahesh Padaki, Ranjith Krishna Pai, M.S. Jyothi, and R. Geetha Balakrishna
- Subjects
Materials science ,Scanning electron microscope ,Mechanical Engineering ,chemistry.chemical_element ,Nanoparticle ,Selective catalytic reduction ,Condensed Matter Physics ,Redox ,chemistry.chemical_compound ,Chromium ,Membrane ,chemistry ,Chemical engineering ,Mechanics of Materials ,Titanium dioxide ,General Materials Science ,Polysulfone - Abstract
The study demonstrates the 100% repeated recyclability of hybrid membranes without any pretreatment. Composite membranes designed with titanium dioxide (TiO2) nanoparticles (NPs) and polysulfone (PSf) membranes were used for reduction of chromium (Cr) (VI) to Cr (III) under sunlight. Different concentrations of TiO2 NPs varying from 1.5% to 2.5% with the difference of 0.5% were incorporated into the membrane matrix. Increase in weight percentage of TiO2 particles enhances the reduction to 100% within 2.5 h with an increase in recyclable capacity as well. The effect of recycling on the surface of the membrane was studied using x-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscopy (AFM). The observations in general indicate an increase in roughness without affecting the catalytic efficiency up to six recycles. The study on surface membrane morphology and catalytic efficiency with reusability opens a scope for a feasible economical chromium reduction via a membrane process. Macro and micro structure of the membrane before reduction and after recycling were studied and compared with scientific evidence. Based on the results, the kinetic model was proposed for the reduction reactions.
- Published
- 2014
38. Synthesis of poly(4, 4′‐biphenylene sulfonyl succinamide)‐polysulfone blend membranes for removal of toxic metal ions from water
- Author
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T M Subrahmanya, Sudesh Yadav, R. Geetha Balakrishna, Mahesh Padaki, Wei-Song Hung, Nagaraj S. Naik, and M.S. Jyothi
- Subjects
Sulfonyl ,chemistry.chemical_classification ,chemistry.chemical_compound ,Membrane ,Polymers and Plastics ,Chemistry ,Metal ions in aqueous solution ,Polymer chemistry ,Materials Chemistry ,General Chemistry ,Polysulfone ,Biphenylene ,Surfaces, Coatings and Films - Published
- 2019
39. Eco-friendly membrane process and product development for complete elimination of chromium toxicity in wastewater
- Author
-
Vignesh Nayak, Khantong Soontarapa, Mahesh Padaki, R. Geetha Balakrishna, and M.S. Jyothi
- Subjects
chemistry.chemical_classification ,Environmental Engineering ,Chromatography ,Chemistry ,Health, Toxicology and Mutagenesis ,Composite number ,chemistry.chemical_element ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,0104 chemical sciences ,Catalysis ,Chromium ,chemistry.chemical_compound ,Membrane ,Chemical engineering ,Photocatalysis ,Environmental Chemistry ,Chromium toxicity ,0210 nano-technology ,Bifunctional ,Waste Management and Disposal - Abstract
Hydrophobic polysulphone (PSf) was reformed into a hydrophilic polymer by sulphonation (via electrophilic substitution) and was subsequently made into a composite by incorporating nano titania to reduce Cr (VI) in the concentrated feed to Cr (III), thus eliminating the hazards of Cr (VI). The modified polymer and its composites were characterized by spectroscopic and microscopic techniques. The composite membranes exhibited enhanced hydrophilicity and flux and were evaluated for the rejection of chromium. The effect of pH and interference of counter ions towards rejection was studied. The charges fixed on the surface of the membrane due to titania, support ionic interactions and facilitated the rejection process. Essentially, rejection of up to 98% was achieved. The innovation of using a bifunctional membrane for the rejection of Cr (VI) together with the removal of its toxicity by photocatalytic reduction, leading to the potential recovery of Cr (III), highlight the uniqueness of this work.
- Published
- 2016
40. Sunlight active PSf/TiO 2 hybrid membrane for elimination of chromium
- Author
-
M.S., Jyothi, primary, Nayak, Vignesh, additional, Padaki, Mahesh, additional, and Balakrishna, R. Geetha, additional
- Published
- 2017
- Full Text
- View/download PDF
41. Preparation and Characterization of Chitosan Thin Films on Mixed-Matrix Membranes for Complete Removal of Chromium
- Author
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Ahmad Fauzi Ismail, M.S. Jyothi, R. Geetha Balakrishna, Vignesh Nayak, and Mahesh Padaki
- Subjects
chemistry.chemical_element ,reduction ,General Chemistry ,Full Papers ,Polyvinyl alcohol ,Contact angle ,Chitosan ,chemistry.chemical_compound ,Chromium ,Adsorption ,Membrane ,chemistry ,Organic chemistry ,Polysulfone ,chromium ,Thin film ,chitosan ,hydrophilicity ,composite membranes ,Nuclear chemistry - Abstract
Herein we present a new approach for the complete removal of Cr(VI) species, through reduction of Cr(VI) to Cr(III), followed by adsorption of Cr(III). Reduction of chromium from water is an important challenge, as Cr(IV) is one of the most toxic substances emitted from industrial processes. Chitosan (CS) thin films were developed on plain polysulfone (PSf) and PSf/TiO2 membrane substrates by a temperature-induced technique using polyvinyl alcohol as a binder. Structure property elucidation was carried out by X-ray diffraction, microscopy, spectroscopy, contact angle measurement, and water uptake studies. The increase in hydrophilicity followed the order: PSfPSf/TiO2PSf/TiO2/CS membranes. Use of this thin-film composite membrane for chromium removal was investigated with regards to the effects of light and pH. The observations reveal 100 % reduction of Cr(VI) to Cr(III) through electrons and protons donated from OH and NH2 groups of the CS layer; the reduced Cr(III) species are adsorbed onto the CS layer via complexation to give chromium-free water.
- Published
- 2014
42. Photoactive Titania Float for Disinfection of Water; Evaluation of Cell Damage by Bioanalytical Techniques
- Author
-
P. D. Laveena, R. Shwetharani, R. Geetha Balakrishna, and M.S. Jyothi
- Subjects
DNA, Bacterial ,Anatase ,Materials science ,Analytical chemistry ,chemistry.chemical_element ,Electrons ,Biochemistry ,Neodymium ,Bacterial Proteins ,X-Ray Diffraction ,X-ray photoelectron spectroscopy ,Malondialdehyde ,Escherichia coli ,Particle Size ,Physical and Theoretical Chemistry ,Titanium ,Microbial Viability ,business.industry ,Photoelectron Spectroscopy ,Doping ,General Medicine ,Photochemical Processes ,Culture Media ,Disinfection ,RNA, Bacterial ,Semiconductor ,chemistry ,Transmission electron microscopy ,Sunlight ,Particle size ,Water Microbiology ,business ,Visible spectrum - Abstract
A photoactive float was fabricated with the modified titania to cause a feasible disinfection of water, contaminated with E. coli. The commercially available titania was doped with neodymium by pulverization technique to enhance its activity in sunlight and a multiapproach technique was used to evaluate the extended efficiency of the doped sample. X-ray diffraction patterns depicted the retention of anatase phase on doping and the existence of neodymium was confirmed by the energy dispersive atomic X-ray analysis and the X-ray photoelectron spectroscopy. Transmission electron microscopy and Bruner-Emmett-Teller analysis depicted a marginal increase in the particle size and a decrease in the surface area, respectively. Doping induces semiconductor behavior with lower band energy that could respond to visible light and exhibit better disinfection activity. The "f" and "d" transitions of the lanthanide in doped sample caused new electronic behavior of trapping/detrapping effect together with bandgap narrowing. The amount of malondialdehyde, protein, DNA and RNA released on destruction of E. coli was observed to be 0.915 × 10(-3) μg mL(-1), 859.912 μg mL(-1), 20.173 μg mL(-1) and 1146.073 μg mL(-1), respectively. The above analytical methods along with standard plate count method substantiated the enhanced disinfection efficiency of the doped sample in sunlight.
- Published
- 2014
43. Eco-friendly membrane process and product development for complete elimination of chromium toxicity in wastewater.
- Author
-
M.S., Jyothi, Nayak, Vignesh, Padaki, Mahesh, Balakrishna, R. Geetha, and Soontarapa, Khantong
- Subjects
- *
ARTIFICIAL membranes , *TOXICOLOGY of chromium , *SULFONES , *SULFONATION , *NEW product development - Abstract
Hydrophobic polysulphone (PSf) was reformed into a hydrophilic polymer by sulphonation (via electrophilic substitution) and was subsequently made into a composite by incorporating nano titania to reduce Cr (VI) in the concentrated feed to Cr (III), thus eliminating the hazards of Cr (VI). The modified polymer and its composites were characterized by spectroscopic and microscopic techniques. The composite membranes exhibited enhanced hydrophilicity and flux and were evaluated for the rejection of chromium. The effect of pH and interference of counter ions towards rejection was studied. The charges fixed on the surface of the membrane due to titania, support ionic interactions and facilitated the rejection process. Essentially, rejection of up to 98% was achieved. The innovation of using a bifunctional membrane for the rejection of Cr (VI) together with the removal of its toxicity by photocatalytic reduction, leading to the potential recovery of Cr (III), highlight the uniqueness of this work. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
44. Sunlight active PSf/TiO2 hybrid membrane for elimination of chromium.
- Author
-
M.S., Jyothi, Nayak, Vignesh, Padaki, Mahesh, and Balakrishna, R. Geetha
- Subjects
- *
TOXICOLOGY of chromium , *PHOTOREDUCTION , *HYDROXYL group , *CHROMIUM in water , *WATER pollution - Abstract
The report aims to develop and use sunlight-active catalyst-membrane to reduce toxic Cr (VI) to less toxic Cr (III) and to reject Cr (III) from Cr contaminated water. Polysulfone and TiO 2 nanoparticles were hybridized, to induce a bifunctional efficacy of metal ion reduction and separation. Reduction of Cr (VI) results in the formation of Cr (III), which is larger in size facilitating rejection. Hybrid membranes possess superior hydrophilicity and permeability with an added advantage of enhanced metal ion reduction and rejection. Photoreduction of Cr (VI) requires the presence of acid to avoid accumulation of holes and hydroxyl radicals in the reaction medium. Cr (III) solution obtained after photoreduction was subjected to direct filtration without any pretreatment, so as to obtain complete Cr-free water. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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