171 results on '"Dipak Rana"'
Search Results
2. Improved permeation, separation and antifouling performance of customized polyacrylonitrile ultrafiltration membranes
- Author
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D. Mohan, Dipak Rana, Alagumalai Nagendran, D. Nithya Rabekkal, Noel Jacob Kaleekkal, and J.S. Beril Melbiah
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General Chemical Engineering ,Ultrafiltration ,Polyacrylonitrile ,Nanoparticle ,02 engineering and technology ,General Chemistry ,Polyethylene glycol ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Biofouling ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Phase inversion (chemistry) ,0210 nano-technology - Abstract
Tailored polyacrylonitrile (PAN) ultrafiltration (UF) membranes are fabricated with Pluronic-F127 and polyethylene glycol phosphate decorated calcium carbonate (PGP-CaCO3) additives with the aim of high water permeation, macromolecular rejection and antifouling properties. The nanoscale CaCO3 synthesis is carried out via a single step carbonization route using PGP as a hydrophilic modifier to introduce hydroxyl groups onto its surface. The topographies of the nanoparticles are investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). PAN/PGP-CaCO3 mixed matrix membranes (MMMs) are fabricated via phase inversion method and examined by attenuated total reflectance-Fourier infra-red spectroscopy (ATR-FTIR), mechanical stability, thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM) to explore the changes in membrane properties due to the well-dispersed PGP-CaCO3 in the PAN membrane matrix. The UF performance of the membranes is investigated in terms of pure water flux, macromolecular rejection and antifouling property. The fouling resistance of membranes is assessed using bovine serum albumin (BSA) and humic acid (HA) as model foulants. The membrane loaded with 0.75 wt.% (M3) of PGP-CaCO3 manifested increased wettability with reduced surface free energy leading to a higher pure water flux of 366 L/m2 h. M3 also displayed a rejection of 93.9% for BSA and 93.2% for HA. The success of the modification can be confirmed as the membrane M3 exhibited lower flux decline and displayed a flux recovery ratio of 90.98% during HA filtration. The results demonstrated the potential use of PAN/PGP-CaCO3 membranes in water treatment.
- Published
- 2020
3. Investigation of the versatility of SPES membranes customized with sulfonated molybdenum disulfide nanosheets for DMFC applications
- Author
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Dipak Rana, Santoshkumar D. Bhat, Avanish Shukla, Kumar Divya, Alagumalai Nagendran, and Meenakshi Sundaram Sri Abirami Saraswathi
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chemistry.chemical_classification ,Materials science ,Nanocomposite ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,02 engineering and technology ,Sulfonic acid ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Contact angle ,Direct methanol fuel cell ,chemistry.chemical_compound ,Fuel Technology ,Membrane ,chemistry ,Chemical engineering ,Thermal stability ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Molybdenum disulfide - Abstract
Sulfonated poly(ether sulfone) (SPES) based proton exchange membranes (PEMs) are fabricated using sulfonated molybdenum disulfide (S-MoS2) nanosheets via facile solution casting method. SPES (DS = 30%) and S-MoS2 are synthesized and sulfonation is evidently observed in FTIR and XRD analysis. The anchoring of sulfonic acid group on exfoliated molybdenum disulfide (E-MoS2) and elemental composition of S-MoS2 are confirmed by XPS spectrum. Physico-chemical characteristics such as ion-exchange capacity (IEC), water uptake, swelling ratio and oxidation stability are found to be increases after the addition of S-MoS2 into SPES matrix. Increment in S-MoS2 content in SPES matrix decreases the surface contact angle due to the increase in hydrophilicity. Further, the dispersing ability of S-MoS2 in SPES matrix is evidently shown by an increase in surface roughness, tensile strength and thermal stability of the SPES/S-MoS2 nanocomposite membranes. On the whole, SPES/S-MoS2-1 membrane showed the highest proton conductivity of 5.98 × 10−3 Scm−1, selectivity of 19.6 × 104 Scm−3s, peak power density of 28.28 mWcm−2 and lesser methanol permeability of 3.05 × 10−8 cm2s−1. The strong interfacial interaction between SPES and S-MoS2 in nanocomposite membranes create strong hydrogen bond network to facilitate the proton conduction pathway via both vehicle and Grotthuss type mechanisms. Overall results suggested that the SPES/S-MoS2 nanocomposite membranes are superior and appropriate alternative for commercially high-cost Nafion® membranes for use in renewable direct methanol fuel cell (DMFC) devices.
- Published
- 2020
4. Effect of tamarind seed polysaccharide on thermogelation property and drug release profile of poloxamer 407-based ophthalmic formulation
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Koushik Dutta, Amartya Bhattacharya, Arghya Adhikary, Dipankar Chattopadhyay, Arijita Basu, Mitali Dewan, and Dipak Rana
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endocrine system ,Biocompatibility ,Hydrochloride ,02 engineering and technology ,010402 general chemistry ,Polysaccharide ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,immune system diseases ,Materials Chemistry ,medicine ,Fourier transform infrared spectroscopy ,Dissolution ,chemistry.chemical_classification ,Chromatography ,virus diseases ,General Chemistry ,Polymer ,Poloxamer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Poloxamer 407 ,0210 nano-technology ,medicine.drug - Abstract
Herein, the potential impact of tamarind seed polysaccharide (TSP) on the gelation nature and in vitro release of a particular drug, pilocarpine hydrochloride, from different poloxamer 407-based ophthalmic formulations were evaluated. The combination of TSP (0.5–1.5 wt%) and 18 wt% poloxamer (PM) solutions resulted in a significant improvement in gel elasticity under physiological conditions. The introduction of TSP to PM not only enhanced the viscosity of the gel, but also stimulated the gelation procedure. Due to the inclusion of TSP, the gel dissolution rate of the PM-based formulation was greatly reduced. The FTIR spectral analysis revealed the interaction between –OH groups of both polymers, resulting in a decline in the gelation temperature of the PM–TSP-based formulations. It was also detected in the cryo-SEM analysis that the pore size of the PM gel decreased and the depth of its pores increased with the inclusion of TSP. Furthermore, the in vitro release analysis indicated that the retention capacity of PM–TSP-based formulations was superior to that of the only PM-based formulation. The SEM study and the cell viability data demonstrated the biocompatibility and non-toxicity of TSP. Therefore, the designed formulation is fairly promising to be utilized as an in situ ophthalmic drug carrier.
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- 2020
5. Mechanical and wear behaviour of poly(vinylidene fluoride)/clay nanocomposite
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Pralay Maiti, Anupama Gaur, and Dipak Rana
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lcsh:TN1-997 ,Morphology (linguistics) ,Materials science ,Modulus ,02 engineering and technology ,01 natural sciences ,law.invention ,Biomaterials ,chemistry.chemical_compound ,law ,0103 physical sciences ,Crystallization ,Fourier transform infrared spectroscopy ,Composite material ,lcsh:Mining engineering. Metallurgy ,010302 applied physics ,Nanocomposite ,Metals and Alloys ,Tribology ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,chemistry ,Spherulite ,Ceramics and Composites ,0210 nano-technology ,Fluoride - Abstract
Poly(vinylidene fluoride) (PVDF)/organically modified nanoclay composites using different amount of nanoclay have been prepared through solution route. The structural changes are determined through X-ray diffraction and Fourier transform infrared spectroscopy studies, which show the transformation from α to β-phase crystallization in presence of nanoclay. Polarised optical microscopic images show the changes of spherulite pattern into mesh like pattern in presence of nanoclay. Modulus of PVDF-nanocomposite increase with increasing the nanoclay content up to 4 wt.% and then slightly decreases under uniaxial tension and the improvement in mechanical responses are fitted with theoretical models. Tribological behaviour of PVDF nanocomposites is evaluated and found that nanoclay content upto 4 wt.% is effective in decreasing the wear and coefficient of friction of PVDF. Similarly, hardness of the nanocomposites also increases for clay content upto 4 wt.%. The nanoclay is working as reinforcing agent for PVDF and is improving its mechanical and frictional properties. Keywords: PVDF, Wear, Hardness, Morphology
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- 2019
6. The performance of polyvinylidene fluoride - polytetrafluoroethylene nanocomposite distillation membranes: An experimental and numerical study
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Christopher Q. Lan, Dipak Rana, Zhelun Li, and Takeshi Matsuura
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Materials science ,Nanocomposite ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Membrane distillation ,Polyvinylidene fluoride ,6. Clean water ,Analytical Chemistry ,Contact angle ,chemistry.chemical_compound ,Membrane ,020401 chemical engineering ,chemistry ,Chemical engineering ,Attenuated total reflection ,0204 chemical engineering ,Phase inversion (chemistry) ,Fourier transform infrared spectroscopy ,0210 nano-technology - Abstract
Supported flat sheet polyvinylidene fluoride - polytetrafluoroethylene (PVDF-PTFE) nanocomposite membranes were fabricated for this study using the phase inversion process. Several characterization methods, such as scanning electron microscopy, atomic force microscopy, attenuated total reflectance - Fourier transform infrared spectroscopy, water contact angle, and liquid entry pressure of water (LEPw) measurements, were carried out on the prepared membranes, and vacuum membrane distillation (VMD) experiments were then applied to test membrane permeabilities. The cooperation of PTFE was demonstrated to have great potential in enhancing the permeate flux of PVDF membranes while maintaining an acceptable LEPw value. At a feed temperature of 30 °C and vacuum pressure 97.54 kPa, the VMD pure water permeates flux of the prepared nanocomposite membrane embedded with 40 wt% PTFE was 5.61 kg/m2·h, while that of pure PVDF membrane was 0.71 kg/m2 h. The salt rejection results of the prepared nanocomposite membranes were all above 99.9%. These results indicate the applicability of the PVDF-PTFE nanocomposite membranes supported on non-woven polyester fiber for desalination.
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- 2019
7. Nano CuO/g-C3N4 sheets-based ultrafiltration membrane with enhanced interfacial affinity, antifouling and protein separation performances for water treatment application
- Author
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Noel Jacob Kaleekkal, Reshika Gnanamoorthi Amimodu, Dipak Rana, and Thanigaivelan Arumugham
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Environmental Engineering ,Materials science ,Polyphenylsulfone ,Ultrafiltration ,02 engineering and technology ,General Medicine ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surface energy ,0104 chemical sciences ,Contact angle ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Nano ,Environmental Chemistry ,Wetting ,Phase inversion (chemistry) ,0210 nano-technology ,General Environmental Science - Abstract
To improve the interfacial affinity and antifouling properties of polyphenylsulfone (PPSU) membrane, nano CuO/g-C3N4 (g-CN) sheets were synthesized via facile calcination route as one pot synthesis method. The uniformly assembled nanohybrid fillers, CuO on g-CN sheets were confirmed by using XRD, TEM, EDX and FTIR analysis. The non-solvent induced phase inversion technique was used to fabricate the nanohybrid ultrafiltration (UF) membranes by doping different concentration (0.5–1 wt.%) of nano CuO/g-C3N4 (g-CN) sheets within the PPSU matrix. The results of contact angle, atomic force microscopy, energy-dispersive X-ray spectroscopy reveal that surface structure and physico-chemical properties of nanohybrid membrane plays lead role in solute interaction and rejection compared to bare membrane, M0. Furthermore, the interfacial affinity of membrane was explored in detail via surface free energy, spreading coefficient, wetting tension and reversible work of adhesion analysis. Nanohybrid UF membrane, with 0.5% of the filler (M1) displayed remarkable permeation flux of 202, 131 L/m2/hr for pure water and protein solution, respectively while maintaining a high protein rejection (96%). Moreover, the exceptional dispersion of the nanosheets in the polymer matrix enhanced FRR (79%) and decreased the overall resistance of M1 compared to the pristine membrane (M0). Overall results suggest that the incorporation of nano sheets is a facile modification technique which improves the comprehensive membrane performance and holds a great potential to be further explored for water treatment.
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- 2019
8. Polythiophenes: An emerging class of promising water purifying materials
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Kingshuk Dutta and Dipak Rana
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Pollutant ,Materials science ,Polymers and Plastics ,Organic Chemistry ,General Physics and Astronomy ,Portable water purification ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Contaminated water ,chemistry.chemical_compound ,Adsorption ,chemistry ,Materials Chemistry ,Photocatalysis ,Polythiophene ,Water treatment ,0210 nano-technology - Abstract
Contamination of water with pollutants that are toxic and/or carcinogenic has led to serious and irreversible consequences to the quality and safety of the water that we consume on a daily basis. This has led to extensive research worldwide to find immediate and effective solutions to this problem. One such practically efficient solution is the treatment of contaminated water for the removal of added contaminants. Among the materials used for water treatment, adsorbents and photocatalysts have been used extensively since they are easy to fabricate, functionalize and use, and they demonstrate high removal efficiencies. Very recently, polythiophene and its derivatives, as well as modified composites of polythiophene and its derivatives, have emerged as extremely promising adsorbent and photocatalyst materials. These materials possess high charge density, surface area and a number of sites to interact and adsorb pollutants. Herein, the research progress achieved so far regarding the fabrication and application of these polythiophene-based adsorbents/photocatalysts toward water purification has been summarized.
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- 2019
9. Effects of multi-walled carbon nanotubes (MWCNTs) and integrated MWCNTs/SiO2 nano-additives on PVDF polymeric membranes for vacuum membrane distillation
- Author
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Christopher Q. Lan, Takeshi Matsuura, Rufan Zhou, and Dipak Rana
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Materials science ,Nanocomposite ,Filtration and Separation ,02 engineering and technology ,Carbon nanotube ,021001 nanoscience & nanotechnology ,Membrane distillation ,Polyvinylidene fluoride ,Desalination ,Analytical Chemistry ,law.invention ,chemistry.chemical_compound ,Membrane ,020401 chemical engineering ,chemistry ,Chemical engineering ,law ,Nano ,0204 chemical engineering ,0210 nano-technology ,Porosity - Abstract
Polyvinylidene fluoride (PVDF) was blended with multi-walled carbon nanotubes (MWCNTs) and MWCNTs/SiO2 nano-additives to fabricate nanocomposite vacuum membrane distillation (VMD) membranes for desalination. The effects of MWCNTs and MWCNTs/SiO2 integrated additives on the morphology and performance of the PVDF membrane were studied. When only MWCNTs were used, 2 wt% loading of MWCNTs to PVDF had the maximum effect on the improvement of VMD flux, due primarily to the enlargement and elongation of the finger-like pores. Then, one of three different SiO2 nanoparticles (NPs) (hydrophobic, superhydrophobic and hydrophilic) was further added to the membrane that already contained 2 wt% of MWCNTs. When the amount of SiO2 NPs was relatively low, VMD flux increased as a result of the synergistic effects between the two filler components, i.e. one is the increase of overall porosity by MWCNTs and the other is the growth of the macrovoids by SiO2 NPs. But among those two, the effect of MWCNTs was more dominant. Compared with the pristine PVDF membrane and the nanocomposite PVDF membrane with a single filler of MWCNTs, respectively, the flux increase by the addition of SiO2 was 292% and 55%. On the other hand, when a relatively large amount of SiO2 NPs was added, the effect of SiO2 NPs started to dominate. Especially, the asymmetric structure of the membrane disappeared, leading to low mechanical strength. All fabricated membranes exhibited great desalination potential with salt rejection as high as >99.97%.
- Published
- 2019
10. Sulfonated poly (ether sulfone) composite membranes customized with polydopamine coated molybdenum disulfide nanosheets for renewable energy devices
- Author
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Alagumalai Nagendran, Dipak Rana, Kumar Divya, and Meenakshi Sundaram Sri Abirami Saraswathi
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Materials science ,Nanocomposite ,Polymers and Plastics ,Organic Chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Contact angle ,chemistry.chemical_compound ,Surface coating ,Membrane ,Sulfonate ,chemistry ,Chemical engineering ,Nafion ,Proton transport ,Materials Chemistry ,0210 nano-technology ,Molybdenum disulfide - Abstract
Sulfonated poly (ether sulfone) (SPES) membranes are fabricated using polydopamine layered molybdenum disulfide (PDM) nanosheets. The exfoliated molybdenum disulfide (E-MoS2) nanosheets are subjected to surface coating with self-polymerization of dopamine and probed by FT-IR and EDAX analysis. Membranes are characterized by FT-IR, XRD, SEM, AFM, contact angle, water uptake, ion-exchange capacity, proton conductivity, methanol permeability, TGA, mechanical and oxidative stability. Characterization results confirmed that the SPES/PDM nanocomposite membranes are better than bare SPES and Nafion-212 membranes possibly due to the interface electrostatic attraction between amine groups (-NH2 and –NH-) of PDM with sulfonate (SO3−) group of SPES which create the strong acid-base pair. This result in the enhancement of the proton transport pathway in nanocomposite membranes and also the PDM reduces the methanol transport channels by generating the tortuous path. SPES/PDM-1 membrane exhibits the highest proton conductivity of 5.64 × 10-3 Scm-1, methanol resistivity of 2.23 × 10-8 cm2s-1 and selectivity of 22 × 104 Scm-3s. SPES/PDM membranes are displayed better thermal, mechanical and oxidative stability probably due to the uniform distribution of PDM on SPES matrix as evidenced by SEM images. Overall results confirmed that the SPES/PDM membranes will be an alternate to expensive Nafion in clean energy DMFC devices.
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- 2019
11. Prediction and optimization of engine characteristics of a DI diesel engine fueled with cyclohexanol/diesel blends
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D. Damodharan, K. Gopal, Balaji Sethuramasamyraja, Dipak Rana, Melvin Victor De Poures, B. Rajesh Kumar, S. Saravanan, and A.P. Sathiyagnanam
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Materials science ,Renewable Energy, Sustainability and the Environment ,020209 energy ,technology, industry, and agriculture ,Cyclohexanol ,Energy Engineering and Power Technology ,Lignocellulosic biomass ,02 engineering and technology ,respiratory system ,Diesel engine ,complex mixtures ,respiratory tract diseases ,chemistry.chemical_compound ,Diesel fuel ,Fuel Technology ,020401 chemical engineering ,Nuclear Energy and Engineering ,chemistry ,Chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,0204 chemical engineering ,human activities ,Derivative (chemistry) - Abstract
This study uses cyclohexanol – a high-carbon, cyclic bio-alcohol which is a derivative of lignocellulosic biomass – in blended form with diesel to power a direct-injection single-cylinder diesel en...
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- 2019
12. Cellulose acetate nanocomposite ultrafiltration membranes tailored with hydrous manganese dioxide nanoparticles for water treatment applications
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Meenakshi Sundaram Sri Abirami Saraswathi, S. Vetrivel, Alagumalai Nagendran, Noel Jacob Kaleekkal, Kumar Divya, and Dipak Rana
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chemistry.chemical_compound ,Membrane ,Materials science ,Nanocomposite ,Polymers and Plastics ,chemistry ,Chemical engineering ,Ultrafiltration ,chemistry.chemical_element ,Nanoparticle ,Water treatment ,Manganese ,Cellulose acetate - Published
- 2019
13. Cellulose acetate ultrafiltration membranes customized with bio-inspired polydopamine coating and in situ immobilization of silver nanoparticles
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Dipak Rana, Alagumalai Nagendran, Meenakshi Sundaram Sri Abirami Saraswathi, Paramasivam Kanimozhi, Shanmugaraj Gowrishankar, and Subbiah Alwarappan
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Chemistry ,General Chemistry ,engineering.material ,Permeation ,Cellulose acetate ,Catalysis ,Silver nanoparticle ,Contact angle ,Biofouling ,Silver nitrate ,chemistry.chemical_compound ,Membrane ,Coating ,Chemical engineering ,Materials Chemistry ,engineering - Abstract
Herein, we report the effect of modification of cellulose acetate (CA) ultrafiltration (UF) membranes via bioinspired polydopamine (PD) coating followed by in situ immobilization of silver nanoparticles (AgNPs). Such a modification resulted in excellent hydrophilicity, contaminant rejection and minimized both organic fouling and bio-fouling properties. PD coating imparts high surface hydrophilicity and anti-organic fouling properties, whereas the immobilized AgNPs provide excellent anti-biofouling properties to the modified membrane. The immobilization of AgNPs on the CA membrane surface is achieved by simple immersion of the membrane into a silver nitrate solution. The catechol groups present in the membrane facilitate the immobilization of AgNPs via a metal coordination. Leaching tests were also conducted to determine the concentration of the AgNPs in the permeate using Atomic Absorption Spectroscopy (AAS) and we inferred that the concentrations are lower than the usual contaminant limit. Also the contact angle (55.8°), pure water flux (113.1 L m−2 h−1) and biofouling experimental results of the modified membranes confirm that there is a significant enhancement in the membrane hydrophilicity, permeability, anti-fouling and anti-biofouling properties when compared to the pristine CA membrane.
- Published
- 2019
14. PFOM fillers embedded PVDF/cellulose dual-layered membranes with hydrophobic–hydrophilic channels for desalination via direct contact membrane distillation process
- Author
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Noel Jacob Kaleekkal, Dipak Rana, Kulathu Iyer Sathiyanarayanan, and Thanigaivelan Arumugham
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Materials science ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Membrane distillation ,01 natural sciences ,Desalination ,Polyvinylidene fluoride ,0104 chemical sciences ,law.invention ,Contact angle ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,law ,Cellulose ,0210 nano-technology ,Distillation - Abstract
In this research work, novel perfluorooctanoic acid-modified melamine (PFOM) was synthesized as a hydrophobic filler using a facile one-pot synthesis. PFOM incorporating polyvinylidene fluoride (PVDF) solution was cast on a cellulose sheet to prepare a dual-layered membrane employing the phase-inversion technique for direct contact membrane distillation (DCMD) application. The influence of PFOM to tailor the dual-layered membrane performance was then investigated. The long perfluoro chain in PFOM hydrophobic fillers increased the surface roughness of the membranes due to its random overlapping with PVDF backbone, and these membranes exhibited a higher water contact angle value. The increase in pore size and membrane porosity did not significantly influence the liquid entry pressure of water (LEPw). The microporous membranes displayed good mechanical strength for use in the test setup. Pure water permeation was the highest (6.9 kg m−2 h−1) for membrane (M1) with 1 wt% of PFOM when tested with a simulated sea-water solution (3.5% w/v NaCl) in the direct contact distillation mode. These membranes also achieved the theoretical salt-rejection of 99.9%, thus confirming the potential of these membranes to be investigated for large scale membrane distillation (MD) applications like desalination of seawater.
- Published
- 2019
15. Fabrication of novel aromatic amine functionalized nanofiltration (NF) membranes and testing its dye removal and desalting ability
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Noel Jacob Kaleekkal, Dipak Rana, and Thanigaivelan Arumugham
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chemistry.chemical_classification ,Ammonium bromide ,Materials science ,Polymers and Plastics ,Polyphenylsulfone ,Metal ions in aqueous solution ,Organic Chemistry ,Aromatic amine ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Membrane ,Chemical engineering ,chemistry ,Nanofiltration ,Crystal violet ,Phase inversion (chemistry) ,0210 nano-technology - Abstract
In this work, novel positively charged NF membranes, decorated with aromatic amine moieties, aminated polyphenylsulfone (PPSU-NH2) were fabricated by the phase inversion technique. The prepared membranes were characterized by scanning electron microscopy, atomic force microscopy, average pore size and molecular weight cut-off. The surface properties of these membranes were determined by ion exchange capacity (IEC), contact angle (CA), surface free energy and water spreading coefficient. The membrane enriched with an aromatic amine (M3) had an overall smoother membrane surface with a pore size of 0.72 nm M3 has a positively charged surface with an IEC of 0.51 meq.g−1 and a highly hydrophilic nature confirmed by a low water CA (∼31°), and the greatest observed pure water flux (∼54 LMH). The amine incorporated membranes showed an increased resistance to fouling when challenged with cetyl trimethyl ammonium bromide as a model foulant, which suggests the existence of repulsive forces shielding the membranes from the positively charged foulants. The M3 showed a considerable rejection of 89 and 93.5% for the multivalent salts CaCl2 and AlCl3, respectively, and expectedly lower rejection of 18.7 and 25.6% for univalent salts Na2SO4 and NaCl, respectively. The prepared membranes demonstrated an exceptional ability in rejection (>99%) of cationic dye crystal violet while maintaining a moderate flux. Therefore, this method of preparation of a positively charged NF membrane can be further investigated for its potential for the removal of dyes and metal ions from commercial waste streams.
- Published
- 2018
16. Customized antifouling polyacrylonitrile ultrafiltration membranes for effective removal of organic contaminants from aqueous stream
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N. Nagendra Gandhi, Dipak Rana, Alagumalai Nagendran, Jegan Stella Beril Melbiah, Pramila Joseph, and Doraiswamy Raju Mohan
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Fouling ,Renewable Energy, Sustainability and the Environment ,Chemistry ,General Chemical Engineering ,Organic Chemistry ,Ultrafiltration ,Polyacrylonitrile ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Inorganic Chemistry ,Biofouling ,chemistry.chemical_compound ,Fuel Technology ,Membrane ,Adsorption ,Chemical engineering ,Water treatment ,Phase inversion (chemistry) ,0210 nano-technology ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Biotechnology - Abstract
BACKGROUND: Ultrafiltration (UF) is a promising separation technique for the removal of macromolecular contaminants. However, the hydrophobic polymeric UF membrane performance suffers from fouling in the long run due to clogging by contaminants at the surface and pores. In this study, anti‐fouling hydrophilic polyacrylonitrile (PAN) UF membranes in the presence of an amphiphilic triblockcopolymer, Pluronic F127 (PF127) were prepared via a phase inversion technique. RESULTS: The effect of varying concentrations of PF127 on PAN UF membranes was analyzed by attenuated total reflectance–Fourier transform infrared spectroscopy (ATR‐FTIR), by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The filtration characteristics of the membranes were measured in terms of pure water flux, membrane porosity and water content. The separation efficiency of the membranes is explored for contaminants such as bovine serum albumin (BSA), humic acid (HA) and oil. The results revealed that the PAN membrane with 4 wt% of PF127 produced greatest permeate flux of 391 L m⁻² h⁻¹ with minimal fouling. A higher solute rejection of more than 90% was observed for the tailored membranes due to the improvement in surface properties. CONCLUSION: The inherent hydrophilicity of the high density poly (ethylene oxide) brush‐like layer of PF127 at the membrane–water interface is utilized effectively to restrict the adsorption of the organic contaminants onto the membrane surface. After simple hydraulic washing of PAN/PF127 UF membranes, the flux recovery ratio was augmented which is ascribed to their excellent antifouling property and potential use in water treatment. © 2018 Society of Chemical Industry
- Published
- 2018
17. Using renewable n-octanol in a non-road diesel engine with some modifications
- Author
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Balaji Sethuramasamyraja, Melvin Victor De Poures, Rajesh Kumar Babu, D. Damodharan, Saravanan Subramani, A.P. Sathiyagnanam, and Dipak Rana
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Octanol ,Waste management ,Renewable Energy, Sustainability and the Environment ,business.industry ,020209 energy ,Energy Engineering and Power Technology ,Biomass ,02 engineering and technology ,Diesel engine ,Combustion ,Renewable energy ,Diesel fuel ,chemistry.chemical_compound ,Fuel Technology ,020401 chemical engineering ,Nuclear Energy and Engineering ,chemistry ,Biofuel ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Exhaust gas recirculation ,0204 chemical engineering ,business - Abstract
n-Octanol is a promising biofuel synthesized from biomass with several properties closer to diesel than the more popularly researched n-butanol. This study investigates the effects of injection tim...
- Published
- 2018
18. Biosurfactant tailored synthesis of porous polypyrrole nanostructures: A facile approach towards CO2 adsorption and dopamine sensing
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Koushik Dutta, Mukut Chakraborty, Ria Ghosh, Dipak Rana, Sutanuka Pattanayak, Dipankar Chattopadhyay, Sriparna De, Nirmal Kumar Bera, Dipankar Mondal, Arpita Adhikari, Sanatan Chattopadhyay, Arijit Halder, and Debajyoti Ghoshal
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Conductive polymer ,Materials science ,Scanning electron microscope ,Mechanical Engineering ,Metals and Alloys ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,Ascorbic acid ,Polypyrrole ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Adsorption ,Chemical engineering ,chemistry ,Mechanics of Materials ,Materials Chemistry ,Cyclic voltammetry ,Fourier transform infrared spectroscopy ,0210 nano-technology - Abstract
Nanostructured conducting polymers are known to function as electroactive materials in sensor devices for adsorption and detection of different analytes. For the purpose of dopamine (DA) detection and CO2 gas adsorption we have prepared nanostructured polypyrrole (PPY) with the help of sodium cholate as surfactant. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) analyses and Brunauer–Emmett–Teller (BET) measurement have been done for the characterization of nanostructure and morphology of the prepared PPY. From the sorption measurement, it is observed that the rodlike PPY structures show highest N2 uptake (91.6 mL g−1) along with appreciable surface area (85.81 m2/g) and porosity (2.53 and 4.51 nm) values. It is also observed that the maximum uptake of CO2 is 173.885 mL g−1 at 195K for the PPY synthesized without any surfactant. Electrochemical characterization of PPY modified glassy carbon electrode (GCE) was done with impedance and cyclic voltammetry experiments. DA sensing in presence of ascorbic acid, uric acid and glucose was done by LSV technique. The PPY modified electrode exhibits sensitivity values of 0.301 and 0.19 μA μM−1 cm2 over two ranges of detection limits of 0.09–0.56 and 10–50 μM for dopamine, respectively (signal/noise = 3).
- Published
- 2018
19. Potency of nanolay on structural, mechanical and gas barrier properties of poly(ethylene terephthalate) Nanohybrid
- Author
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Dipti Saxena, Narendren Soundararajan, Pralay Maiti, Vimal Katiyar, Dipak Rana, and Karun Kumar Jana
- Subjects
chemistry.chemical_classification ,Toughness ,Thermoplastic ,Materials science ,Ethylene ,Polymers and Plastics ,Organic Chemistry ,Modulus ,02 engineering and technology ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Amorphous solid ,Oxygen transmission rate ,chemistry.chemical_compound ,chemistry ,Vickers hardness test ,Materials Chemistry ,Composite material ,0210 nano-technology - Abstract
Thermoplastic and amorphous poly(ethylene terephthalate)/clay nanohybrids have been prepared through solution route. Organically modified NK75 nanoclay has been used as filler in different concentrations to enhance the properties. The Young’s modulus has increased significantly (66%) though there is slight reduction in toughness. Halpin Tsai and Hui-Shia models have been fitted well to explain the nature of stiffness for the prediction of the modulus values. Vicker hardness test has shown considerable improved hardness (16%) in nanohybrids and are nicely predicted using the modified rule of mixture model. The effect of uniaxial stretching on the structural development is explored through small angle X-ray scattering and wide angle XRD. The nanoclay has induced short range ordering upon stretching in nanohybrids as compared to pure PET. Nanoclay has induced high barrier for gas permeation in nanohybrids in comparison to pristine PET. Oxygen transmission rate has also been found to decrease up to 38% for using meager amount of nanoclay. The experimental permeability data has been fitted with different models and has been found suitable for its real applications.
- Published
- 2020
20. Non-Nafion-based cation exchange membranes for direct methanol fuel cells
- Author
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Kumar Divya, M. Sri Abirami Saraswathi, Dipak Rana, and Alagumalai Nagendran
- Subjects
Chemical energy ,chemistry.chemical_compound ,Membrane ,Materials science ,chemistry ,Nafion ,Electric potential energy ,Proton exchange membrane fuel cell ,Nanotechnology ,Cellulose ,Environmentally friendly ,Methanol fuel - Abstract
Driven by the growing interest to reduce dependence on fossil-based energy resources and their severe impacts on the environment, the global community has to turn their attention toward sustainable and eco-friendly energy resources and green technologies. Direct methanol fuel cells (DMFCs) are known to be environmentally friendly devices to convert chemical energy to electrical energy. It has many excellent characteristics such as high energy density and high reliability. Therefore it is considered as a reliable power source, and researchers are trying to use DMFCs to different applications. A critical analysis was performed about the basic concepts and recent developments of proton exchange membranes (PEMs) focusing mainly on its performance in the field of DMFC applications. Particularly, this chapter summarizes the recent results and contributions of some of the important alternate synthetic polymeric materials [such as sulfonated poly(ether ether ketone), SPES, SPEES, and SPVDF-co-HFP] and different classes of biopolymers (such as cellulose, chitosan, alginates, and carrageenan) as base materials for PEM fuel cell applications instead of commercially costly Nafion perfluorinated membranes. Further, this chapter discusses the methods of incorporation of different additives and their influence in enhancing the overall performance of the DMFCs. A special emphasis is given to the proton-conducting and methanol-permeation properties of the membranes with different modification techniques.
- Published
- 2020
21. The rubber–filler interaction and reinforcement in styrene butadiene rubber/devulcanize natural rubber composites with silica–graphene oxide
- Author
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Soumyajit Ghorai, Debapriya De, Dipankar Mondal, Dipankar Chattopadhyay, and Dipak Rana
- Subjects
Filler (packaging) ,Materials science ,Styrene-butadiene ,Polymers and Plastics ,Graphene ,Oxide ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Natural rubber ,chemistry ,law ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Composite material ,0210 nano-technology ,Reinforcement - Published
- 2018
22. Sulfonated poly (ether sulfone)/poly (vinyl alcohol) blend membranes customized with tungsten disulfide nanosheets for DMFC applications
- Author
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Meenakshi Sundaram Sri Abirami Saraswathi, Kumar Divya, Alagumalai Nagendran, Subbiah Alwarappan, and Dipak Rana
- Subjects
Vinyl alcohol ,Materials science ,Nanocomposite ,Polymers and Plastics ,Organic Chemistry ,Intercalation (chemistry) ,Tungsten disulfide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Direct methanol fuel cell ,Membrane ,chemistry ,Chemical engineering ,Materials Chemistry ,Thermal stability ,Methanol ,0210 nano-technology - Abstract
Sulfonated poly (ether sulfone) (SPES) and poly (vinyl alcohol) (PVA) blend nanocomposite proton exchange membranes were fabricated and tailored with exfoliated tungsten disulfide (E-WS2) nanosheets with the aim of achieving better methanol resistant properties for direct methanol fuel cell (DMFC) applications. Reinforcement due to the existence of E-WS2 nanosheets on composite membrane imparted superior mechanical and thermal stability. Surface morphology of the composite membranes in terms of roughness is examined by AFM. Further, the results confirmed the intercalation of E-WS2 nanosheets onto the polymer matrix. The incorporation of E-WS2 nanosheets onto SPES/PVA system shows highest proton conductivity of 1.18 × 10−2 Scm−1 (at 25 °C) and mechanical stability of 143 MPa upon comparison with pristine SPES membrane. Furthermore, the methanol absorption by membrane matrix is found to be 3.42 × 10−8 cm2s−1. Overall results confirmed that SPES/PVA/E-WS2 nanocomposite proton exchange membranes are promising for applications in DMFCs.
- Published
- 2018
23. Cellulose acetate composite membranes tailored with exfoliated tungsten disulfide nanosheets: Permeation characteristics and antifouling ability
- Author
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Dipak Rana, Kumar Divya, S. Vetrivel, Alagumalai Nagendran, and M. Sri Abirami Saraswathi
- Subjects
Materials science ,Biofouling ,Tungsten disulfide ,Ultrafiltration ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Permeability ,Tungsten ,Contact angle ,chemistry.chemical_compound ,Structural Biology ,Animals ,Cellulose ,Molecular Biology ,Nanocomposite ,Fouling ,Water ,Membranes, Artificial ,Serum Albumin, Bovine ,General Medicine ,Permeation ,021001 nanoscience & nanotechnology ,Cellulose acetate ,Nanostructures ,0104 chemical sciences ,Membrane ,Chemical engineering ,chemistry ,Cattle ,0210 nano-technology ,Hydrophobic and Hydrophilic Interactions - Abstract
An attempt has been made to demonstrate the effects of exfoliated tungsten disulfide (E-WS2) nanosheets on the fabrication, permeation and anti-fouling performance of cellulose acetate (CA) ultrafiltration membranes. The E-WS2 was prepared and characterized in terms of energy dispersive X-ray spectroscopy (EDXS) and X-ray diffraction spectroscopy (XRD). Pure and composite CA membranes were methodically characterized for its surface, chemical and morphological structure using FT-IR, XRD, SEM and water contact angle analysis. Filtration characteristics of membranes such as pure water flux, porosity and hydraulic resistance were also studied. The addition of E-WS2 nanosheets exhibited significant improvement in the surface hydrophilicity of composite membranes than the control CA membrane and are evidenced by the observed contact angle and porosity values. However at 1 wt% E-WS2 concentration, CA membrane showed lower water flux (92.3 ± 0.5) due to the pore plugging effect. The flux recovery ratio (FRR), bovine serum albumin (BSA) rejection, reversible and irreversible fouling experimental results suggested that CA/E-WS2 (1 wt%) UF membranes possess better fouling resistance potential than control CA membrane as a result of enhanced hydrophilicity. This study emphasizes the strong interplay between CA and E-WS2 nanosheets which play a significant role in altering the permeation and antifouling characteristics of nanocomposite membranes.
- Published
- 2018
24. Custom-made sulfonated poly (ether sulfone) nanocomposite proton exchange membranes using exfoliated molybdenum disulfide nanosheets for DMFC applications
- Author
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Dipak Rana, Kumar Divya, Subbiah Alwarappan, Alagumalai Nagendran, and Meenakshi Sundaram Sri Abirami Saraswathi
- Subjects
Thermogravimetric analysis ,Materials science ,Nanocomposite ,Polymers and Plastics ,Scanning electron microscope ,Organic Chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Contact angle ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Ultimate tensile strength ,Materials Chemistry ,0210 nano-technology ,Selectivity ,Molybdenum disulfide - Abstract
Exfoliated molybdenum disulfide (E-MoS2) incorporated sulfonated poly ether sulfone (SPES) nanocomposite proton exchange membranes (PEMs) were made by solution casting method. E-MoS2 was synthesized from bulk MoS2 powder by ultrasonication and SPES was prepared by sulfonation of PES using sulfuric and chlorosulfonic acid. Surface characterization of these membranes have been performed using several techniques such as Fourier transformed infra-red spectroscopy, x-ray diffraction, atomic force microscopy, scanning electron microscopy and contact angle measurements. In order to assess the physicochemical performance of the membranes, water uptake, swelling ratio and ion exchange capacity (IEC) of the membranes were measured. Thermal and mechanical stability of the nanocomposite PEMs were probed by thermogravimetric, analysis and tensile strength measurement respectively. Physicochemical characteristics such as water uptake, IEC, swelling ratio, thermal and mechanical stability of SPES/E-MoS2 nanocomposite PEMs were increased upon comparison with the bare SPES PEM. Tensile strength of SPES-1 nanocomposite PEM (117 MPa) is doubled upon comparison with pure SPES PEM (60 MPa). AFM images of PEMs nanocomposite revealed that surface roughness and nodular size were increased upon the addition of E-MoS2. Electrochemical performance of nanocomposite membranes such as proton conductivity, selectivity and methanol permeability were investigated and results confirmed that SPES/E-MoS2 nanocomposite membranes exhibited better performance than bare SPES PEM. More specifically, SPES membrane incorporated with 1 wt% E-MoS2 (SPES-1) exhibited higher proton conductivity (3.17 × 10−3 Scm−1), selectivity (8.43 × 104 Scm−3s) and lower methanol permeability (0.376 × 10−7 cm2s−1). From the results, it is evident that SPES-1 PEM nanocomposites are better candidate for applications in DMFCs.
- Published
- 2018
25. Highly selective and methanol resistant polypyrrole laminated SPVdF-co-HFP/PWA proton exchange membranes for DMFC applications
- Author
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Alagumalai Nagendran, Kumar Divya, A. Uma Devi, Dipak Rana, and M. Sri Abirami Saraswathi
- Subjects
Materials science ,Composite number ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Polypyrrole ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,Nafion ,General Materials Science ,Phosphotungstic acid ,Methanol ,In situ polymerization ,0210 nano-technology ,Methanol fuel - Abstract
A series of poly (vinylidene fluoride-co-hexafluoropropylene)/phosphotungstic acid/polypyrrole [SPVdF-co-HFP/PWA/PPY- n, where ‘n’ denotes the number of times the PPY coating process was repeated] composite proton exchange membranes (PEMS) were fabricated and studied for its suitability in direct methanol fuel cells (DMFCs). In situ polymerization was used for the lamination of polypyrrole (PPY) on the SPVdF-co-HFP/PWA membrane surface to diminish the leaching of phosphotungstic acid (PWA). FT-IR analysis confirmed the blending of PWA to SPVdF-co-HFP and the coating of PPY on the composite PEM. AFM study indicated that the surface roughness of the composite membrane was decreased by increasing in PPY layer. Ion exchange capacity, water uptake and swelling ratio of the SPVdF-co-HFP/PWA membranes were decreased whereas tensile strength was increased by increasing the PPY layer. The hydrophobic PPY leads to a substantial drop in methanol crossover with workable levels of proton conductivity. The methanol crossover of SPVdF-co-HFP/PWA/PPY-5 hybrid PEM was found to be 1.73 × 10−7 cm2s−1 and was much lower than Nafion-117 (63 × 10−7 cm2s−1). The selectivity ratio of SPVdF-co-HFP/PWA/PPY-5 was found to be high (2.77 × 104 Scm-3s). Thus, all the experimental results revealed that the SPVdF-co-HFP/PWA/PPY composite membrane could be an alternative to high-priced Nafion.
- Published
- 2018
26. Insight Studies on Metal-Organic Framework Nanofibrous Membrane Adsorption and Activation for Heavy Metal Ions Removal from Aqueous Solution
- Author
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Christopher Q. Lan, Takeshi Matsuura, Dipak Rana, and Johnson E. Efome
- Subjects
Materials science ,Aqueous solution ,Metal ions in aqueous solution ,fungi ,Polyacrylonitrile ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Electrospinning ,0104 chemical sciences ,chemistry.chemical_compound ,Membrane ,Adsorption ,Chemical engineering ,chemistry ,Nanofiber ,General Materials Science ,Metal-organic framework ,0210 nano-technology - Abstract
Electrospun nanofiber composite membranes containing water-stable metal-organic frameworks (MOFs) particles (Zr-based MOF-808) supported on polyacrylonitrile (PAN) nanofiber synthesized via co-electrospinning have been prepared. MOF particles were dispersed in the organic polymer, and their subsequent presence was inferred by scanning electron microscopy. Membrane performance in heavy metal ion adsorption in batch filtration was evaluated on the basis of Cd2+ and Zn2+ ions sequestration. The adsorption capacities of the pristine MOF and the MOF composite membrane revealed that MOF particles in the membrane could be accessed for adsorption in the hydrophilic PAN membranes. The maximum adsorption capacities were 225.05 and 287.06 mg g–1 for Cd2+ and Zn2+, respectively. Conventional thermal activation of pristine MOF and composite membrane revealed a crystal downsizing, while “hydractivation” produced an expanded MOF with enhanced adsorption potentials. The PAN/MOF-808 “hydractivated” composite membrane coul...
- Published
- 2018
27. Synthesis of methylcellulose/cellulose nano-crystals nanocomposites: Material properties and study of sustained release of ketorolac tromethamine
- Author
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Dipankar Chattopadhyay, Dipak Rana, Nayan Ranjan Saha, Dibyendu Mondal, Swapan Kumar Ghosh, Jonathan Tersur Orasugh, Gunjan Sarkar, and Roshnara Mishra
- Subjects
Materials science ,Fabrication ,Polymers and Plastics ,Diffusion ,02 engineering and technology ,Methylcellulose ,010402 general chemistry ,01 natural sciences ,Ketorolac Tromethamine ,Nanocomposites ,chemistry.chemical_compound ,Spectroscopy, Fourier Transform Infrared ,Materials Chemistry ,Cellulose ,Fourier transform infrared spectroscopy ,Transdermal ,chemistry.chemical_classification ,Nanocomposite ,Organic Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,Casting ,0104 chemical sciences ,chemistry ,Chemical engineering ,Nanoparticles ,0210 nano-technology - Abstract
Non-toxic nanocomposites based bio-films obtained from methylcellulose (MC) can reduce environmental problems associated with synthetic polymers. A new facile route for the isolation of cellulose nano-crystals (CNC) from jute waste is successfully utilized here. The fabrication of CNC reinforced MC nanocomposites by film casting technique and the studies of the effect of CNC on the properties of the MC based nanocomposites have been reported. The synthesized nanocomposites have shown improved UV resistance, mechanical, barrier, and thermal properties. FTIR results established the physicochemical compatibility between the drug, MC and CNC in nanocomposites. In vitro permeation studies performed by using Franz diffusion cell revealed diffusion mediated sustained drug release from the devices due to the presence of interaction between MC and CNC through H-bonding, electrostatic interaction between the hydrophilic polymer/CNC chains with the drug and the formation of tortuous path. The nanocomposites can be used for edible packaging and transdermal drug delivery.
- Published
- 2018
28. Permeation characteristics of tailored poly (m-phenylene isophthalamide) ultrafiltration membranes and probing its efficacy on bovine serum albumin separation
- Author
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J. Pramila, Dipak Rana, J.S. Beril Melbiah, Alagumalai Nagendran, D. Mohan, and N. Nagendra Gandhi
- Subjects
Materials science ,Polymers and Plastics ,biology ,Organic Chemistry ,Ultrafiltration ,02 engineering and technology ,Permeation ,021001 nanoscience & nanotechnology ,Contact angle ,chemistry.chemical_compound ,Membrane ,020401 chemical engineering ,Chemical engineering ,chemistry ,PEG ratio ,biology.protein ,0204 chemical engineering ,Phase inversion (chemistry) ,Bovine serum albumin ,0210 nano-technology ,Ethylene glycol - Abstract
Poly (m-phenylene isophthalamide) (PMIA) ultrafiltration (UF) membranes has been prepared using lithium chloride (LiCl) and poly (ethylene glycol) of average molecular weight 600 Da (PEG 600) as additives by phase inversion technique. Membranes were characterized by FTIR, TGA, DTG and UTM. Surface characteristics are probed by SEM, AFM and water contact Angle. It was evidenced from SEM analysis that all membranes have macrovoids in its structure and hence possess high water permeability. Accordingly, all membranes were highly hydrophilic in nature which can be predicted from water wettability and work of adhesion measurement using contact angle. Further, membranes were subjected for protein rejection study using bovine serum albumin (BSA) as a model foulant and its fouling ability was analyzed. It has been found that the 10 wt.% PMIA membrane with 2 wt% of PEG 600 and 4 wt.% of LiCl has high water permeability and better reversible and irreversible antifouling capability than any other prepared membranes. Flux recovery ratio (FRR) of 91% was obtained for the 10 wt.% PMIA also confirmed it is one of the promising UF membrane materials.
- Published
- 2018
29. A facile comparative approach towards utilization of waste cotton lint for the synthesis of nano-crystalline cellulose crystals along with acid recovery
- Author
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Dibyendu Mondal, Swapan Kumar Ghosh, Gunjan Sarkar, Dipankar Chattopadhyay, Dipak Rana, Jonathan Tersur Orasugh, and Nayan Ranjan Saha
- Subjects
Materials science ,Dispersity ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Nanomaterials ,Nanocellulose ,chemistry.chemical_compound ,Crystallinity ,X-Ray Diffraction ,Dynamic light scattering ,Structural Biology ,Spectroscopy, Fourier Transform Infrared ,Zeta potential ,Thermal stability ,Cotton Fiber ,Cellulose ,Molecular Biology ,General Medicine ,021001 nanoscience & nanotechnology ,Crystallins ,Dynamic Light Scattering ,Nanostructures ,0104 chemical sciences ,chemistry ,Chemical engineering ,Thermogravimetry ,Crystallization ,0210 nano-technology - Abstract
There is a need for reuse of waste cotton lint (WCL) from the blow room of yarn spinning mills. The drive to use this material for the synthesis of nanocellulose is difficult because of the several purification/pretreatment processes. Here, we developed a combined single bath purification process of WCL and utilized it for the synthesis of nano-crystalline cellulose crystals (NCs) which are valuable nanomaterials with novel properties along with acid recovery for reuse. The micrograph of the synthesized NCs confirmed a network of nano-sized crystalline cellulose crystals having nano ranged diameter of NCs isolated by two processes. The FTIR result established the removal of impurities and hemicelluloses from WCL. The crystallinity index of WCL (∼89.97%) is improved to ∼96% and ∼94% for sulphuric acid and nitric acid synthesized NCs (NC1 and NC2). The crystallite size of WCL, CTWCL, NC1, and NC2 was calculated using XRD and found to be 101.56, 103.54, 98.81, and 95.6nm respectively. The hydrodynamic size (Z-average) (dnm), polydispersity index and zeta potential of NCs was also studied using dynamic light scattering (DLS). The thermal stability of the NC1 is better than that of NC2. These NCs can be used as reinforcing filler/barrier material.
- Published
- 2018
30. Separation of bovine serum albumin and humic acid contaminants from aqueous stream using tailored poly (amide imide) ultrafiltration membranes
- Author
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Kumar Divya, Alagumalai Nagendran, M. Sri Abirami Saraswathi, Dipak Rana, S. Mahalakshmi, and S. Vetrivel
- Subjects
biology ,Process Chemistry and Technology ,Ultrafiltration ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,0104 chemical sciences ,chemistry.chemical_compound ,Membrane ,Chemical engineering ,chemistry ,PEG ratio ,Polyamide ,biology.protein ,Chemical Engineering (miscellaneous) ,Bovine serum albumin ,Fourier transform infrared spectroscopy ,Phase inversion (chemistry) ,0210 nano-technology ,Waste Management and Disposal ,Ethylene glycol - Abstract
An attempt of studying the effects of the Pluronic F127 (triblock-co-polymer) and pore forming PEG 600 [poly (ethylene glycol) of average molecular weight 600 Da] additives in enhancing the hydrophilicity and antifouling properties of poly (amide imide) (PAI) ultrafiltration (UF) membranes was made. PAI membranes were fabricated by the addition of optimized amount of 5 wt.% of Pluronic F127 and PEG 600 additives individually via phase inversion technique and characterized in terms of scanning electron microscopy (SEM), contact angle (CA),work of adhesion (ωA), Fourier transform infrared spectroscopy (FT-IR), pure water flux (PWF), hydraulic resistance (Rm) and percent water content (%WC). Percent solute rejection (%SR) and permeate flux were measured using BSA (bovine serum albumin) and HA (humic acid) as modal fouling agents. Antifouling capacity of the membranes were studied by the experiments such as flux recovery ratio (FRR), reversible fouling (Rr) and irreversible fouling (Rir). The results obtained from the above mentioned characterizations revealed that the PAI/Pluronic F127 membrane exhibits better performance than that of PAI/PEG 600 membrane due to the dual performance of Pluronic F127 as pore former as well as hydrophilic surface modifier causes superior enhancement in the membrane hydrophilicity. Moreover, the strong interactions between the PAI and PEG 600, limits the performance of PAI/PEG 600 membrane. Hence, Pluronic F127 has a greater influence in effectively modifying the PAI membrane than PEG 600.
- Published
- 2018
31. Tailored SPVdF-co-HFP/SGO nanocomposite proton exchange membranes for direct methanol fuel cells
- Author
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Appadurai Uma Devi, Dipak Rana, Kumar Divya, Alagumalai Nagendran, and Noel Jacob Kaleekkal
- Subjects
Materials science ,Nanocomposite ,Polymers and Plastics ,Polymer nanocomposite ,Organic Chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Direct methanol fuel cell ,Membrane ,chemistry ,Chemical engineering ,Materials Chemistry ,Methanol ,0210 nano-technology ,Selectivity ,Methanol fuel ,Sulfanilic acid - Abstract
Sulfonated poly (vinylidenefluoride-co-hexafluoropropylene) (SPVdF-co-HFP) based polymer nanocomposite proton exchange membranes (PEMs) were successfully fabricated in the presence of sulfonated graphene oxide (SGO) as nano-filler for direct methanol fuel cell (DMFC) applications. Sulfonation of GO was carried out using sulfanilic acid and the incorporation of -SO3H groups were confirmed by FTIR, HR-TEM and Raman spectroscopy. The physicochemical properties of the fabricated membranes such as ion exchange capacity (IEC), water uptake (WU), swelling ratio (SR), oxidative, thermal and mechanical stability, proton conductivity, methanol permeability and membrane selectivity were determined. Among the various nanocomposite PEMs were prepared, SPVdF-co-HFP/SGO-7 exhibited good tensile strength (29.7 MPa), improved Young's modulus (432.5 MPa), high proton conductivity (5.52 × 10−3 S/cm, at 30 °C), superior selectivity (2.99 × 104 Scm−3s) and reduced methanol cross-over (1.846 × 10−7cm2s−1) and this nanocomposite membrane can possibly be a superior and alternate candidate to Nafion membrane in DMFCs.
- Published
- 2018
32. Fabrication of cellulose acetate nanocomposite membranes using 2D layered nanomaterials for macromolecular separation
- Author
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Dipak Rana, M. Sri Abirami Saraswathi, Alagumalai Nagendran, and S. Vetrivel
- Subjects
Materials science ,Biofouling ,Macromolecular Substances ,Ultrafiltration ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Nanocomposites ,Nanomaterials ,Contact angle ,chemistry.chemical_compound ,X-Ray Diffraction ,Structural Biology ,Tensile Strength ,Spectroscopy, Fourier Transform Infrared ,Polymer chemistry ,Animals ,Nanotechnology ,Disulfides ,Cellulose ,Molecular Biology ,Molybdenum disulfide ,Molybdenum ,Nanocomposite ,Water ,Membranes, Artificial ,Serum Albumin, Bovine ,General Medicine ,021001 nanoscience & nanotechnology ,Cellulose acetate ,0104 chemical sciences ,Membrane ,Chemical engineering ,chemistry ,Cattle ,Graphite ,0210 nano-technology ,Hydrophobic and Hydrophilic Interactions ,Porosity - Abstract
Cellulose acetate (CA) nanocomposite ultrafiltration (UF) membranes were fabricated using 2D layered nanosheets such as graphene oxide (GO) and exfoliated molybdenum disulfide (E-MoS2) and effectively used for the removal of macromolecular protein. The GO and E-MoS2 nanosheets were prepared and characterized by FT-IR and XRD respectively. GO and E-MoS2 (0.5wt.%) were blended individually with CA. The assenting changes generated by the incorporation of GO and E-MoS2 in terms of surface hydrophilicity of the nanocomposite membrane were analyzed by pure water flux (PWF) and contact angle measurement. The influence of 2D nanosheets on the morphology of CA are studied by scanning electron microscopy (SEM). Mechanical strength and hydraulic resistance of the nanocomposite membranes were found to be improved compared to bare CA membrane. The separation and antifouling performance of the nanocomposite membranes were studied using macromolecular bovine serum albumin (BSA). From the results, it was observed that a CA/GO-0.5 membrane exhibited the highest PWF (125.4±1.7Lm-2h-1), water content (70.6±1.2%), porosity (34.6±1.7%), flux recovery ratio (FRR) (88.8±1.6%) and lowest contact angle (63.9±2.5°), hydraulic resistance (4.3±0.67kPa/Lm-2h -1) than pure CA and CA/E-MoS2-0.5 membranes. CA/GO-0.5 membrane displayed superior UF and antifouling performance due to the greater affinity of GO nanoparticles towards water.
- Published
- 2018
33. Jute cellulose nano-fibrils/hydroxypropylmethylcellulose nanocomposite: A novel material with potential for application in packaging and transdermal drug delivery system
- Author
-
Jonathan Tersur Orasugh, Dipak Rana, Nayan Ranjan Saha, Atiskumar Chattoapadhyay, Md. Masud Rahaman Mollick, Dipankar Chattopadhyay, Bhairab Chandra Mitra, Gunjan Sarkar, Dibyendu Mondal, and Swapan Kumar Ghosh
- Subjects
Filler (packaging) ,Nanocomposite ,Materials science ,technology, industry, and agriculture ,macromolecular substances ,02 engineering and technology ,Dynamic mechanical analysis ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Food packaging ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Lignin ,Hemicellulose ,Cellulose ,0210 nano-technology ,Agronomy and Crop Science ,Transdermal - Abstract
Nowadays, bio-derived cellulose nano-fibrils based nanocomposites is gaining utmost interest in the area of barrier films for food packaging, as reinforcing filler to make biodegradable nanocomposites with different biopolymers for various applications such as transdermal drug delivery, edible packaging and tissue scaffolding. Ultrasound-assisted preparation of hydroxypropylmethylcellulose based nanocomposites with cellulose nano-fibrils were carried out following solution mixing technique. The crystalline nature of cellulose nano-fibrils has been scrutinized by X-ray diffraction study. The field emission-scanning electron micrographs of cellulose nano-fibrils revealed a network of nano-fibrillar morphology. The Fourier transform infrared spectroscopy results of cellulose nano-fibrils confirmed the removal of lignin and hemicellulose from raw jute (Corchorus olitorius L.) fibres. The storage modulus and tensile properties of hydroxypropyl methylcellulose films increased up to the addition of 1.00 wt% cellulose nano-fibrils. The moisture affinity of hydrophilic hydroxypropylmethylcellulose has also been reduced at 1.00 wt% cellulose nano-fibrils loading. The impact of cellulose nano-fibrils loading on the cumulative percentage of drug release from prepared nanocomposites films has been explored accordingly. By utilizing these versatilities of cellulose nano-fibrils, the fabricated nanocomposites are expected to be highly promising in the area of packaging and transdermal drug delivery system.
- Published
- 2018
34. A comparative assessment of ternary blends of three bio-alcohols with waste cooking oil and diesel for optimum emissions and performance in a CI engine using response surface methodology
- Author
-
V. Krishnamoorthy, R. Dhanasekaran, B. Rajesh Kumar, S. Saravanan, and Dipak Rana
- Subjects
Smoke ,Engineering ,Waste management ,Renewable Energy, Sustainability and the Environment ,business.industry ,020209 energy ,Butanol ,Energy Engineering and Power Technology ,02 engineering and technology ,Pulp and paper industry ,chemistry.chemical_compound ,Brake specific fuel consumption ,Diesel fuel ,Fuel Technology ,Nuclear Energy and Engineering ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,Yellow grease ,Response surface methodology ,Ternary operation ,business ,NOx - Abstract
Recycling waste cooking oil (WCO) for use in diesel engines offers a sustainable solution for ecological wellbeing and energy security. Diesel-WCO-alcohol ternary blends provide a straightforward and cost-effective opportunity to utilise both a bio-component & a recycled component to partially replace diesel and to reduce viscosity of WCO instead of expensive pre-heating and trans-esterification. Three bio-alcohols, n-propanol (Pr), n-butanol (Bu) and n-pentanol (Pe) were chosen for this purpose. An investigation was carried out to compare the effects of adding three bio-alcohols to form ternary blends with WCO and diesel (D) individually (D50-WCO30-Pr20, D50-WCO30-Bu20 and D50-WCO30-Pe20) for optimum engine characteristics by employing a response surface methodology (RSM) based optimization using a 3-factor × 3-level full factorial experimental design. Three alcohols, three injection timings (23°, 25° and 27°CA bTDC) and three EGR rates (10, 20 and 30%) were chosen as factors and their levels. Regression models were developed for NOx, smoke, HC, CO, BTE and BSFC and were found to be statistically significant. Interactive effects between injection timing and EGR for all blends were presented. Pentanol was found to be a suitable alcohol for this purpose as the ternary blend D50-WCO30-Pe20 injected at 23°CA bTDC at 15% EGR had the highest desirability. Confirmatory tests validated that the models developed were adequate and the error in prediction is within 6%.
- Published
- 2018
35. Metal–organic frameworks supported on nanofibers to remove heavy metals
- Author
-
Takeshi Matsuura, Dipak Rana, Christopher Q. Lan, and Johnson E. Efome
- Subjects
Materials science ,Aqueous solution ,Renewable Energy, Sustainability and the Environment ,Polyacrylonitrile ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Polyvinylidene fluoride ,6. Clean water ,0104 chemical sciences ,chemistry.chemical_compound ,Membrane ,Adsorption ,chemistry ,Chemical engineering ,Nanofiber ,Desorption ,General Materials Science ,Water treatment ,0210 nano-technology - Abstract
Fe(III) and Zr(IV) based metal–organic frameworks (MOFs) were enmeshed in polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) electro-spun nanofibers to produce nanofibrous MOF membranes (NMOM). The pristine MOFs showed high adsorption capacity for lead ions and mercury ions from aqueous solution. The Fe(III) based MOFs with PAN based NMOM exhibited a high flux of 348 L m−2 h−1 with a permeance of 870 L m−1 h−1 bar−1. At room temperature, the NMOM could treat 395 mL of 100 ppb Pb(II) solution, while maintaining a drinking water standard of
- Published
- 2018
36. Bio-derived cellulose nanofibril reinforced poly(N-isopropylacrylamide)-g-guar gum nanocomposite: An avant-garde biomaterial as a transdermal membrane
- Author
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Koushik Dutta, Jonathan Tersur Orasugh, Dipankar Chattopadhyay, Sumit Kar, Dipak Rana, Rajdeb Banerjee, Roshnara Mishra, Dipankar Mondal, Beauty Das, and Arpita Adhikari
- Subjects
Nanocomposite ,Guar gum ,Polymers and Plastics ,Chemistry ,Organic Chemistry ,Transdermal route ,Biomaterial ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Chemical engineering ,Materials Chemistry ,Poly(N-isopropylacrylamide) ,Diltiazem hydrochloride ,Cellulose ,0210 nano-technology ,Transdermal - Abstract
The delivery of diltiazem hydrochloride in therapeutical doses has attracted an immense research interest. However, its slower penetration through the transdermal route has stipulated to develop a competent transdermal membrane. Therefore, a nanocomposite based patch was formulated by exploring co-polymer and jute derived nano-cellulose. Poly(N-isopropylacrylamide) was grafted into guar gum (GG-g-PNIPAAm) with different feeding ratios. The co-polymer formation was authenticated by FTIR and 13C NMR spectra. The nanocomposite were prepared by incorporating nanofibre (0.5–2 wt%) into GG-g-PNIPAAm. The structural and morphological studies supported good interactions and presence of nano-cellulose on co-polymer. GG-g-PNIPAAm has showed higher thermostability than guar gum. Moreover, the addition of CNF has improved the thermo-mechanical and barrier properties of the nanocomposite. The nanocomposite containing 1 wt% CNF was found to be best performing. The patch showed in-vitro cyto-compatibility and non-irritant behaviour. The in-vitro release study of best nanocomposite revealed controlled drug release capability with 7.78 and 22.9% after 5 and 20 h, respectively.
- Published
- 2018
37. Highly selective custom‐made chitosan based membranes with reduced fuel permeability for direct methanol fuel cells
- Author
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Dipak Rana, Laila Rameesha, Kumar Divya, Alagumalai Nagendran, and Meenakshi Sundram Sri Abirami Saraswathi
- Subjects
Chitosan ,chemistry.chemical_compound ,Membrane ,Materials science ,Polymers and Plastics ,chemistry ,Chemical engineering ,Permeability (electromagnetism) ,Materials Chemistry ,General Chemistry ,Highly selective ,Methanol fuel ,Surfaces, Coatings and Films - Published
- 2021
38. Effect of gellan gum on the thermogelation property and drug release profile of Poloxamer 407 based ophthalmic formulation
- Author
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Manas Bhowmik, Beauty Das, Dipankar Chattopadhyay, Atis Kumar Chattoapadhyay, Mitali Dewan, Dipak Rana, and Gunjan Sarkar
- Subjects
Models, Molecular ,Hydrochloride ,Chemistry, Pharmaceutical ,Molecular Conformation ,Administration, Ophthalmic ,Poloxamer ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Structural Biology ,Ophthalmic drug ,medicine ,Molecular Biology ,Dissolution ,chemistry.chemical_classification ,Drug Carriers ,Chromatography ,Viscosity ,Polysaccharides, Bacterial ,Pilocarpine ,Temperature ,General Medicine ,Polymer ,021001 nanoscience & nanotechnology ,Gellan gum ,0104 chemical sciences ,Drug Liberation ,chemistry ,Poloxamer 407 ,Drug release ,0210 nano-technology ,Gels ,medicine.drug - Abstract
The effect of gellan gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3wt% gellan gum and 18wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of gellan gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-gellan gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of gellan gum and in-vitro release studies indicate that PM-gellan gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
- Published
- 2017
39. Fabrication and electrochemical properties of highly selective SPES/GO composite membranes for direct methanol fuel cells
- Author
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A. Muthumeenal, M. Sri Abirami Saraswathi, Dipak Rana, and Alagumalai Nagendran
- Subjects
Materials science ,Graphene ,Process Chemistry and Technology ,Composite number ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Pollution ,0104 chemical sciences ,law.invention ,Direct methanol fuel cell ,chemistry.chemical_compound ,Membrane ,Chemical engineering ,chemistry ,law ,Chemical Engineering (miscellaneous) ,Methanol ,0210 nano-technology ,Selectivity ,Waste Management and Disposal ,Methanol fuel ,Nuclear chemistry - Abstract
Graphene oxide (GO) was synthesized and used as an additive at various proportions with the intention of fabrication of sulfonated poly (ether sulfone) (SPES) based composite proton exchange membranes (PEMs) for direct methanol fuel cell (DMFC) applications. Among the various composite membranes prepared, SPES/GO (1 wt%) was found to have the highest selectivity with a water uptake of 40.1%, proton conductivity of 4.3 × 10 −3 S/cm, and methanol permeability of 4.923 × 10 −8 cm 2 /s. The introduction of GO in membranes not only improved proton conductivity, but also positively affected the mechanical properties and the blocking of methanol molecules passing through the membrane. Consequently, the incorporation of GO into SPES membrane has considerably increased the selectivity of the membrane. Therefore, SPES/GO membranes showed three folds increase in performance than original SPES membrane, and hence acted as a good candidate for use in DMFC in order to resolve current issues of methanol crossover.
- Published
- 2017
40. Screening oxygenates for favorable NOx/smoke trade-off in a DI diesel engine using multi response optimization
- Author
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S. Saravanan, Dipak Rana, Balaji Sethuramasamyraja, and B. Rajesh Kumar
- Subjects
Smoke ,020209 energy ,General Chemical Engineering ,Organic Chemistry ,Energy Engineering and Power Technology ,02 engineering and technology ,Diesel engine ,Pulp and paper industry ,Diesel fuel ,Taguchi methods ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Diethyl ether ,Dimethyl carbonate ,Oxygenate ,NOx - Abstract
This study proposes the use of Grey-Taguchi based multi-response optimization to screen suitable diesel-oxygenate blends for achieving simultaneous reduction of smoke and NOx emissions with maximum performance in a DI diesel engine with minimum number of trials. The effects of factors such as oxygenate type, its blend proportion with diesel and retarded injection timing on emission and performance variables were considered. Three popular oxygenates viz., Diethyl ether (DEE), Dimethyl carbonate (DMC) and Diglyme (DGM) were screened. Response surface models (RSM) were developed using experimental data. Taguchi’s signal-to-noise ratio approach was applied to predict optimal factor settings for all individual responses. RSM and predicted optimum factor levels were later validated by rigorous experimentation. It was found that DEE blends delivered best performance. Lowest smoke opacity was realized with DMC blends. NOx emissions were least for DEE blends. Higher DMC and DGM blends generated low HC emissions while lower DGM blends gave out low HC emissions at lower retarded injection timing. CO emissions were generally low for higher DMC blends. Smoke and NOx reducing capabilities of DGM are in between DEE and DMC. Finally it was experimentally validated that, Grey-Taguchi predicted combination of 10% DGM blend injected at 21°CA, simultaneously reduced smoke opacity(▾29.17%) and NOx emissions(▾17.4%) with best performance(▴7%) when compared to baseline diesel operation. The results indicated that Grey-Taguchi method can be effectively used to screen oxygenates suitable to achieve the set objective with minimum number of trials saving cost and time.
- Published
- 2017
41. Magnetoconductivity and electrical transport of polyaniline coated ternary carbide Ti0.9Al0.1C
- Author
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Ajit Kumar Meikap, Dipak Rana, P.S. Mukherjee, and K. Gupta
- Subjects
010302 applied physics ,Materials science ,Condensed matter physics ,General Physics and Astronomy ,02 engineering and technology ,Dielectric ,Conductivity ,021001 nanoscience & nanotechnology ,01 natural sciences ,Variable-range hopping ,law.invention ,Field emission microscopy ,chemistry.chemical_compound ,chemistry ,law ,0103 physical sciences ,Polyaniline ,Density of states ,0210 nano-technology ,Alternating current ,Ternary operation - Abstract
In this paper, we report the mechanism of electrical transport properties of polyaniline coated Ti0.9Al0.1C prepared by chemical route. Samples are characterized by X-ray diffraction technique and morphology has been observed by field emission scanning electron microscope. Semiconducting behavior is obtained for the samples and this behavior has been analyzed by different existing models. Out of different models the Mott’s variable range hopping is the most suitable for analyzing the dc conductivity at lower temperatures. Correlated barrier hopping type of charge transfer process is followed in alternating current conductivity. We observe a transformation from negative to positive dc and ac magnetoconductivity by incorporating Ti0.9Al0.1C in polyaniline. Dielectric properties and impedance analysis are described by Maxwell–Wagner capacitor model. We determine different parameters like localization length, hopping distance, density of states from the analysis of the experimental data. The theory regarding magnetic field dependent ac conductivity is insufficient. This result will be a significant hint for a new theoretical challenge.
- Published
- 2017
42. Studies of the kinetics and mechanism of the removal process of proflavine dye through adsorption by graphene oxide
- Author
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Debabrata Mandal, Mukut Chakraborty, Dipak Rana, Gunjan Sarkar, Dipankar Chattopadhyay, Dipankar Mondal, Tapas Kumar Ghosh, Indranil Roy, Amartya Bhattacharyya, and Nayan Ranjan Saha
- Subjects
Inorganic chemistry ,Oxide ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,symbols.namesake ,chemistry.chemical_compound ,Adsorption ,law ,Materials Chemistry ,Freundlich equation ,Physical and Theoretical Chemistry ,Fourier transform infrared spectroscopy ,Spectroscopy ,Proflavine ,Graphene ,Chemistry ,Langmuir adsorption model ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,symbols ,0210 nano-technology ,Raman spectroscopy - Abstract
Proflavine, a nitrogen-containing dye is used for DNA staining and as an efficient marker, however, it is harmful to body cells, and its efficient removal is essential. In this work, graphene oxide (GO) has been used as an adsorbent for the removal of the dye through the process of adsorption. Though GO is now being used as an adsorbent for the removal of industrial dyes, very few experiments have been done on biologically useful dyes. GO is synthesized from graphite powder by the modified Hummer's method and is characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), Raman and ultra-violet spectroscopies, etc. These characterization techniques indicate the presence of oxygen containing functional groups, e.g., carbonyl, carboxyl and hydroxyl groups on the graphene sheets. These sheets are held well apart by these groups. Parameters like concentration of the adsorbent, pH and temperature have been varied to find the optimum conditions for the most efficient removal of the dye molecules from the solution. Then, for the optimum external conditions, the time dependence of the adsorption was analyzed using pseudo-first and pseudo-second orders kinetics. The adsorption isotherms were also obtaining throws light on the mechanism of the adsorption process which we investigated further by using FTIR characterization.
- Published
- 2017
43. Cellulose nanofibrils/chitosan based transdermal drug delivery vehicle for controlled release of ketorolac tromethamine
- Author
-
Atis Kumar Chattopadhyay, Gunjan Sarkar, Nayan Ranjan Saha, Dipankar Chattopadhyay, Dipak Rana, Jonathan Tersur Orasugh, Amartya Bhattacharyya, and Indranil Roy
- Subjects
Biocompatibility ,Scanning electron microscope ,Chemistry ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Controlled release ,Catalysis ,0104 chemical sciences ,Chitosan ,chemistry.chemical_compound ,Chemical engineering ,Materials Chemistry ,Fourier transform infrared spectroscopy ,Cellulose ,Nanocarriers ,0210 nano-technology ,Transdermal - Abstract
Cellulose nanofibrils (CNFs) have attracted attention as a promising material in the biomedical field because of their outstanding properties such as hydrophilicity, biocompatibility, biodegradability, and high surface area. In this work, we have prepared cellulose nanofibrils from jute fibres (JF), to develop a CNF/chitosan transdermal film for the delivery of ketorolec tromethamine (KT) where the CNFs act as an elegant nanometric carrier. The KT-loaded CNF/chitosan transdermal film matrices have been characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Fourier transform infrared spectroscopy (FTIR) reveals the successful KT loading into the CNF/chitosan transdermal film. Scanning electron microscopy (SEM) study shows the different morphological features of the CNF/chitosan transdermal films. The crystalline nature of the CNF/chitosan transdermal films has been analyzed by X-ray diffraction study. Release profiles from the CNF/chitosan matrices indicate that the drug release rate is sustained with the incorporation of CNFs. We believe that this new nanocarrier may be a potential choice for transdermal drug delivery systems.
- Published
- 2017
44. Extraction and characterization of waste plastic oil (WPO) with the effect of n -butanol addition on the performance and emissions of a DI diesel engine fueled with WPO/diesel blends
- Author
-
S. Saravanan, D. Damodharan, B. Rajesh Kumar, Dipak Rana, and A.P. Sathiyagnanam
- Subjects
Thermal efficiency ,Materials science ,Waste management ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Butanol ,Energy Engineering and Power Technology ,Fraction (chemistry) ,02 engineering and technology ,Diesel engine ,chemistry.chemical_compound ,Diesel fuel ,Ultra-low-sulfur diesel ,Fuel Technology ,Nuclear Energy and Engineering ,chemistry ,Biofuel ,n-Butanol ,0202 electrical engineering, electronic engineering, information engineering - Abstract
With growing global energy demands, recovering energy from waste plastic presents an attractive avenue to explore as it promotes recycling. Oil synthesized from waste plastic can be excellent fuel for diesel engines but yields higher carcinogenic smoke emissions and poor performance than fossil diesel (D). This study demonstrates the extraction and characterization of waste plastic oil (WPO) obtained by pyrolysis in a laboratory scale batch reactor and later sets out to investigate the effects of adding a renewable oxygenated component in the form of n -butanol (B), a naturally occurring biofuel. Three ternary blends, D50-WPO40-B10, D50-WPO30-B20 and D50-WCO20-B30 were strategically prepared to utilize both a recycled component (WPO by up to 40%) and a renewable component ( n -butanol by up to 30%). The performance and emissions of DI diesel engine when fueled with these blends was then analyzed in comparison with both neat WPO and diesel operation. Results indicated that n -butanol addition presented lower smoke emissions and higher HC emissions when compared to diesel. Addition of 10% n -butanol by vol . to WPO/ULSD blend reduced NO x emissions favorably when compared to both WPO and diesel. However NO x emissions were higher than the corresponding WPO case for higher volume n -butanol blends. Brake thermal efficiency (BTE) of the engine increased with increasing n -butanol fraction in the blends when compared to WPO. Fuel consumption of ternary blends was found to be better than WPO. D50-WPO40-B10 blend presented less NO x and smoke emissions with improvement in engine performance when compared to diesel. Study revealed that n -butanol could be a viable additive for diesel engines operating with WPO extracted from mixed waste plastic.
- Published
- 2017
45. Tailored PVDF nanocomposite membranes using exfoliated MoS2 nanosheets for improved permeation and antifouling performance
- Author
-
Subbiah Alwarappan, Dipak Rana, Meenakshi Sundaram Sri Abirami Saraswathi, Alagumalai Nagendran, and Prabu Vijayakumar
- Subjects
Nanocomposite ,Chemistry ,Ultrafiltration ,02 engineering and technology ,General Chemistry ,Permeation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Contact angle ,chemistry.chemical_compound ,Membrane ,Chemical engineering ,Materials Chemistry ,Phase inversion (chemistry) ,0210 nano-technology ,Porosity ,Molybdenum disulfide - Abstract
Exfoliated molybdenum disulfide (E-MoS2) nanosheets were synthesized from bulk MoS2. Poly(vinylidene fluoride) (PVDF) was incorporated into E-MoS2 to yield nanocomposite ultrafiltration (UF) membranes by the phase inversion technique. Various proportions of E-MoS2 (0.1, 0.5 and 0.8 wt%) were prepared and were characterized in terms of permeation and antifouling properties. FT-IR and XRD studies confirmed the presence of E-MoS2 in the membranes. Moreover, SEM and FESEM/EDX analysis of the membranes confirmed the increase in the porosity and presence, respectively, of E-MoS2. Atomic force microscopy (AFM) images confirmed that the membrane with 0.5 wt% E-MoS2 exhibited a uniform surface structure with (Ra = 35 nm), compared to the pure PVDF membrane (Ra = 37.6 nm). In addition, the membrane with 0.5 wt% E-MoS2, exhibited higher pure water flux (PWF) (105.1 L m−1 h−1), water content (73.7%), porosity (12.24%), bovine serum albumin (BSA) solute rejection (92.3%), least mechanical stability (1.13 MPa), hydraulic resistance (7.44 kPa L−1 m−2 h−1) and contact angle (72.8°). From all these, it is evident that the overall PVDF membrane performance was enhanced by the E-MoS2 addition, and the membrane with 0.5 wt% E-MoS2 outperformed the other counterparts due to its versatile characteristics and superior potential in the water treatment.
- Published
- 2017
46. Studies on carboxylated graphene oxide incorporated polyetherimide mixed matrix ultrafiltration membranes
- Author
-
Dipak Rana, A. Thanigaivelan, D. Mohan, and Noel Jacob Kaleekkal
- Subjects
Materials science ,Graphene ,Ultrafiltration ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Polyetherimide ,01 natural sciences ,law.invention ,Contact angle ,chemistry.chemical_compound ,Membrane ,Chemical engineering ,chemistry ,law ,Zeta potential ,General Materials Science ,Thermal stability ,Fourier transform infrared spectroscopy ,Composite material ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
In this work the graphene oxide prepared by the modified Hummers’ method was effectively carboxylated. These carboxylated graphene oxide (c-GO) microsheets was characterized by X-ray diffraction analysis, Raman shift, zeta potential, and their morphology was observed using a high resolution scanning/transmission electron microscopy. Polyetherimide mixed matrix membranes (MMMs) were fabricated by the non-solvent induced phase separation technique with varying concentration of this microsheet. The presence of these microsheets on the membrane surface was confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy and could also be confirmed visually by optical images. The membranes were further characterized; they showed a greater water flux, higher porosity, and sufficient thermal stability. Incorporation of these microsheets improved the hydrophilicity of the membrane confirmed by the lower contact angle values, which in turn explained the lower interfacial free energy, the increase in work of adhesion, the higher solid-vapor free energy and the spreading coefficient. Membranes loaded with 0.3 wt% of c-GO showed a flux recovery of 94% and only a small flux decline even after 180 min of filtration of humic acid (HA) solution. The efficiency of these membranes in removal of HA, toxic metal ions was also investigated. The bacterial anti-adhesion property of c-GO in the membranes was also explored using Escherichia coli, as a model bio-foulant. The charge of the microsheets and their unique architecture imparts higher hydrophilicity and greater fouling resistance along with improved permeation flux when incorporated into the polymer matrix.
- Published
- 2017
47. Superior biomaterials using diamine modified graphene grafted polyurethane
- Author
-
Dipak Rana, Sanjeev K. Pandey, Ashish Dwivedi, Vivek Gupta, Pralay Maiti, Dinesh K. Patel, and Vinod K. Aswal
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Biocompatibility ,Graphene ,Organic Chemistry ,Biomaterial ,Nanotechnology ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Diamine ,Materials Chemistry ,Surface modification ,0210 nano-technology ,Drug carrier ,Polyurethane - Abstract
s Surface modification of graphene oxide has been performed using diamine moieties with varying chain length and subsequently chemically grafted with long chain polyurethane for wrapping up of graphene sheet with large polymer chains. Functionalization of graphene and its subsequent grafting have been verified through spectroscopic measurements like NMR, FTIR and UV–visible spectroscopy and the uniform dispersion of graphene sheet in polyurethane matrix is achieved. Nanohybrids exhibit better thermal and mechanical responses along with greater self-assembly as compared to pure polymer. Nanometer dimension molecular sheet to gradual increased size of the order of tens of nanometer, hundreds of nanometer to micron scale assembly has been captured through XRD, small angle neutron scattering, AFM and optical microscopy, respectively. Nature of self-assembly associated with stronger interactions sustain the release of embedded drug (anticancerous dexamethasone) from nanohybrid and larger size of inhomogeinities for longer spacer length further sustain the drug release and thereby able to control the release rate of drug by articulating the chemistry of graphene modifications with suitable spacer length of diamine. Biocompatibility of the nanohybrids is verified with cell line studies using human breast cancer cells MDA-MB-231in terms of cell viability, cell adhesion, fluorescence image, reactive oxygen species and mitochondrial tracker measurements indicating better responses of nanohybrid vis-a-vis pure polyurethane. Thus, the control release of the dexamethasone drug from the nanohybrids along with better biological responses clearly suggests a novel biomaterial for the drug carrier.
- Published
- 2016
48. Design of an efficient and selective adsorbent of cationic dye through activated carbon - graphene oxide nanocomposite: Study on mechanism and synergy
- Author
-
Nayan Ranjan Saha, Amartya Bhattacharyya, Indranil Roy, Soumitra Ghorai, Dipankar Chattopadhyay, Gunjan Sarkar, Sriparna De, Dipak Rana, Jonathan Tersur Orasugh, and Sourav Sadhukhan
- Subjects
Langmuir ,Nanocomposite ,Graphene ,Cationic polymerization ,Oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,Adsorption ,chemistry ,Chemical engineering ,law ,medicine ,General Materials Science ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Activated carbon ,medicine.drug - Abstract
A nanocomposite of activated carbon (AC) and graphene oxide (GO) has been used as adsorbent of methylene blue (MB) dye from solution. FTIR spectroscopy, XRD, SEM imaging, size and zeta potential analysis of the nanocomposite material indicate retention of the essential features of both the components responsible for adsorption. Parameters like pH, temperature, adsorbent and salt concentrations, etc. were varied to optimize the adsorption. A very significant increase in adsorption by this nanocomposite, compared to those arising from the individual components, could be observed, resulting in an adsorption capacity of up to 1000 mg/gm. Fit of the data to kinetic equations gave rate constants for the process. Good fits to both Langmuir and Freundlisch isotherms indicated that the contribution of electrostatic attraction between the charged groups present in the composite and dye molecules, as well as the adsorption through AC surface pores both play significant roles. The synergy of these two different mechanisms yields the extraordinarily large adsorption capacity. This factor, together with the cheapness of the material, and its selectivity towards cationic dyes suggest its practical importance for water decontamination.
- Published
- 2021
49. Effects of Polymer Ratio and Film-Penetration Time on the Properties and Performance of Nanocomposite PVDF Membranes in Membrane Distillation
- Author
-
Christopher Q. Lan, Dipak Rana, Takeshi Matsuura, Mohammadali Baghbanzadeh, and Nadine Hirceaga
- Subjects
Materials science ,Nanocomposite ,General Chemical Engineering ,technology, industry, and agriculture ,02 engineering and technology ,General Chemistry ,Penetration (firestop) ,021001 nanoscience & nanotechnology ,Membrane distillation ,Polyvinylidene fluoride ,Industrial and Manufacturing Engineering ,Polyester ,chemistry.chemical_compound ,Membrane ,020401 chemical engineering ,Chemical engineering ,chemistry ,Polymer ratio ,Polymer chemistry ,Immersion (virtual reality) ,0204 chemical engineering ,0210 nano-technology - Abstract
Nanocomposite membranes were prepared for vacuum membrane distillation (VMD) by casting the dope suspension on top of a nonwoven polyester backing material. The dope consisted of 7.0 wt % hydrophilic SiO2 nanoparticles and a polyvinylidene fluoride (PVDF) blend of high molecular weight (H) and low molecular weight (L). The effects of the blend ratio (H:L) and the penetration time (τ), defined as the period between the completion of membrane casting and the immersion in the coagulation bath, on the membrane properties and performance were studied. It was found that the VMD flux is governed by the pore size and thickness of the top layer (defined as the layer formed above the backing material), both of which are affected by the H:L ratio and the penetration time. Results indicate that the VMD flux increased as the portion of L in the casting dope increased at constant τ, while a maximum flux was observed at τ = 2 min when the penetration time was changed at constant H:L ratio. It was also observed that the ...
- Published
- 2016
50. Combined effect of injection timing and exhaust gas recirculation (EGR) on performance and emissions of a DI diesel engine fuelled with next-generation advanced biofuel – diesel blends using response surface methodology
- Author
-
S. Saravanan, Alagumalai Nagendran, Dipak Rana, and B. Rajesh Kumar
- Subjects
Renewable Energy, Sustainability and the Environment ,Isobutanol ,business.industry ,020209 energy ,Energy Engineering and Power Technology ,02 engineering and technology ,Diesel engine ,Automotive engineering ,chemistry.chemical_compound ,Diesel fuel ,Brake specific fuel consumption ,Fuel Technology ,Nuclear Energy and Engineering ,chemistry ,Biofuel ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Response surface methodology ,Exhaust gas recirculation ,business ,NOx - Abstract
Advanced biofuels like dimethyl-carbonate (DMC), isobutanol and n -pentanol can be derived from non-food based biomass feedstock without unsettling food supplies and biodiversity. An experimental and statistical investigation was carried out to analyze the effects of injection-timing and exhaust gas recirculation (EGR) on performance and emissions of a DI diesel engine using advanced biofuel/diesel blends (containing 8 wt% oxygen). Engine characteristics were measured under high-load condition using moderate EGR (up to 30%) and injection-timing modification (up to ±2°CA bTDC) for controlling charge-dilution and combustion-phasing. Multiple regression models developed using response surface methodology (RSM) for measured responses like nitrogen oxides (NOx), smoke opacity and brake specific fuel consumption (BSFC) were found to be statistically significant by analysis of variance (ANOVA). Interactive effects between injection timing and EGR for all blends were analyzed using response surface plots that were fitted using developed models. Optimization was performed using desirability approach of the RSM to minimize NOx and smoke emissions simultaneously with minimum BSFC. Isobutanol/diesel blend injected at 22°CA bTDC without EGR was predicted to be optimum for the tested engine. Confirmatory tests validated that the models developed using RSM are adequate to describe the effects of the injection timing and EGR on performance and emissions characteristics using all blends as the error in prediction is within 5%.
- Published
- 2016
Catalog
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