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Graphene and its related materials are important areas of research in recent years owing to their unique properties. The wide-range industrial application of graphene-related compounds has led to the development of novel and simple methods for the synthesis of graphene. In this paper, an environmentally friendly green synthesis for the partial reduction of graphene oxide (GO) to reduced GO (RGO) in a cost-effective single-step mechanism was reported. The method completely avoids the use of toxic and environmentally harmful reducing agents commonly used in the chemical reduction of GO to obtain RGO. The reduction of GO was carried out using aqueous leaf extracts of Paederia foetide L. The prepared GO and green RGO were characterized by ultraviolet–visible, Raman and Fourier transform infra-red spectroscopic analysis which showed a clear indication of the partial removal of oxygen-containing groups from the GO and the formation of RGO. The morphology of the green RGO was characterized by transmission electron and scanning electron microscopy. Dynamic light scattering was used for zeta potential measurement and correlated with the morphology of the sheets. Electrical conductivity was also measured to check the extent of reduction of GO to RGO.

Hydrophobic anticancer drug, raloxifene hydrochloride (RH) is intercalated into a series of magnesium aluminum layered double hydroxides (LDHs) with various charge density anions through ion exchange technique for controlled drug delivery. The particle nature of the LDH in presence of drug is determined through electron microscopy and surface morphology. The release of drug from the RH intercalated LDHs was made very fast or sustained by altering the exchangeable anions followed by the modified Freundlich and parabolic diffusion models. The drug release rate is explained from the interactions between the drug and LDHs along with order-disorder structure of drug intercalated LDHs. Nitrate bound LDH exhibits greater interaction with drug and sustained drug delivery against the loosely interacted phosphate bound LDH-drug, which shows fast release. Cell viability through MTT assay suggests drug intercalated LDHs as better drug delivery vehicle for cancer cell line against poor bioavailability of the pure drug. In vivo study with mice indicates the differential tumor healing which becomes fast for greater drug release system but the body weight index clearly hints at damaged organ in the case of fast release system. Histopathological experiment confirms the damaged liver of the mice treated either with pure drug or phosphate bound LDH-drug, fast release system, vis-à-vis normal liver cell morphology for sluggish drug release system with steady healing rate of tumor. These observations clearly demonstrate that nitrate bound LDH nanoparticle is a potential drug delivery vehicle for anticancer drugs without any side effect.

Polyacrylonitrile precursor fibers prepared using a solvent-free coagulation process were stabilized, carbonized, and physically activated by carbon dioxide into activated carbon fibers (ACFs). The activation temperature varied from 600 to 900°C while the activation time was 1h. Atomic force microscopy was used to observe the surface morphology, as well as the surface roughness of the ACFs. Higher pyrolysis temperature formed rougher surfaces, and increased the pore sizes. Meanwhile, Fourier transform infrared spectroscopy revealed more conversion of oxygen containing functional groups to carbonaceous materials as the activation temperature increased. Moreover, the microstructure properties were thoroughly characterized by the X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) studies. XRD analysis showed that the activation of the ACFs shrank the ordered structure, reducing the D-spacing from 0.358 to 0.347nm for the fibers prepared at activation temperatures of 600 to 900°C. Meanwhile, XPS analysis concluded that that the oxygen containing functional groups were still retained even at high activation temperatures while the nitrogen containing functional groups were reduced during the high temperature activation in the CO2 atmosphere.

Sulfonated poly (vinylidene fluoride-co-hexafluoropropylene) (SPVDF-co-HFP) based nanocomposite proton exchange membranes (PEM) are fabricated by simple solution casting method using polydopamine coated exfoliated molybdenum disulfide (PDA-MoS2) nanosheets as an alternative for Nafion® in vanadium redox flow batteries (VRFBs). PDA-MoS2 is synthesized by the etching of exfoliated MoS2 nanosheets with dopamine molecule by self-polymerization method. Various characteristic results clearly demonstrated that the incorporated PDA-MoS2 nanosheets homogeneously distributed into the SPVDF-co-HFP matrix and the presence of NH/NH2 group electrostatically interacts with SPVDF-co-HFP to form a strong acid-base pair and thus enhances the proton transport via Grotthuss type mechanism. Besides, the improvement in surface hydrophilicity provides the vehicle type conduction also. As a result, SPVDF-co-HFP/PM nanocomposite membranes showed higher proton conductivity in comparison with the pristine membrane. Especially SPVDF-co-HFP/PM-1 membrane demonstrated the excellent proton conductivity of 5.24 × 10−3 Scm−1 at 25 °C, lower vanadium-ion permeability of 1.05 × 10−8 cm2min−1 and highest membrane selectivity of 49.9 × 104 Scm−3min. On the other hand, vanadium-ion stability of the membrane increased by adding the PD-MoS2 content is attributed to their strong electrostatic attraction towards the polymer matrix. Overall results suggested that the SPVDF-co-HFP/PM-1 nanocomposite membrane is found to be a better alternative for commercially costly Nafion in VRFB applications.

The low-level sensing of ethanol has gained enormous importance due to its application in human health monitoring, road safety, fermentation and food industries. In this investigation, we report the synthesis of ribbonlike nanostructures of polypyrrole (PPY), a conducting polymer, using sodium cholate micelles as a soft template. The PPY nanoribbons were found to exhibit good sensor response along with high degree of selectivity to ethanol vapour as opposed to several common volatile organic compounds (VOCs) showing its suitability as a selective sensing layer to detect ethanol from a mixture containing ethanol, methanol, 2-propanol, toluene, n-hexane, and humidity. The sensing mechanism and its selectivity to ethanol vapor were explained by considering a hydrogen bond type interaction of the OH groups of ethanol molecules with large number of N or NH groups of the PPY available on the surface due to its nanoribbon morphology. Investigation of the cytotoxicity of the PPY nanoribbons revealed good biocompatibility.

Poly(vinylidene fluoride) (PVDF) ultrafiltration (UF) membranes are fabricated using the incorporation of sulfonated graphene oxide (SGO) nanosheets with the aim of enhanced separation of biomacromolecular protein and natural organic matter. The effect of the addition of SGO on the PVDF membrane is evaluated with specific emphasis on morphology, surface hydrophilicity, pure water flux (PWF), bovine serum albumin (BSA) and humic acid (HA) separation. The experimental results revealed that the PVDF membrane with 2 wt.% SGO exhibited the enhanced PWF of 155.5 Lm-2 h-1 and more than 98% of BSA and HA rejection due to its improved hydrophilicity and more porous morphology. The antifouling ability of the PVDF membranes is improved to a great extent with the incorporation of SGO nanosheets is confirmed by the greater than 95% of flux recovery ratio during the filtration of BSA and HA. SGO inherits useful functional groups from graphene oxide and possesses better miscibility with the incorporated polymer matrix due to the presence of strongly charged -SO3- units which is attributed to the relatively enhanced hydrophilicity of the modified membranes. Especially, SGO has extensively employed in membrane-based water treatment as SGO promotes better water permeability performances, together with adequate resistance towards hydraulic pressure. In view of these entire outcomes, it is apparent that the SGO incorporated PVDF nanocomposite UF membrane proves the potential for water and wastewater treatment applications.

An environment-friendly approach for the synthesis of reduced graphene oxide/nickel oxide nanocomposites (RGO/NiO NCs) was done in a microwave via in-situ co-precipitation and hydrothermal mode. A non-toxic aqueous phytoextract was used as a reducing cum stabilizing agent. X-ray diffraction, Raman spectra, Fourier transform infrared spectroscopy analysis confirmed the chemical structure of the NCs. The morphological studies were investigated by scanning electron microscopy, high resolution transmission electron microscopy and energy disperse X-ray. The optical study was verified by UV–visible absorption spectroscopy. The photo-degradation activity was performed at visible light by exposing the methylene blue (MB) dye solution along with the NCs. Experimental result reveals the improved photo-catalytic activity of the NCs towards the photo-degradation of MB (93%) compare to pure NiO NPs (65%) and RGO (negligible). In the nanocomposites, the electronic charge transfer takes place superficially from NiO nanoparticles (NPs) to RGO, effectively delays the electron-hole pair (e−-h+) recombination effect and increases the decomposition rate of the dye solution to some greater extent. The antibacterial activity of the NCs shows impressive potentiality in different culture media contrast with its constituent.

In this study, the effects of incorporation of nanoparticles (NPs), including 7 nm TiO2, 200 nm TiO2, and hydrophilic and hydrophobic SiO2 with a mean diameter in the range of 15–20 nm, and their concentrations on the membrane properties and vacuum membrane distillation (VMD) performance were evaluated. The effect of membrane thickness and support materials were also investigated. The membranes were characterized extensively in terms of water contact angle, liquid entrance pressure of water (LEPw), scanning electron microscopy, surface roughness, and pore size. While the best polyvinylidene fluoride (PVDF) nanocomposite membranes with 200 nm TiO2 NPs were obtained at 2 wt% NPs concentration, the optimal NPs concentration was 5% when 7 nm TiO2 was integrated. Using a nanocomposite membrane containing 2 wt% TiO2 − 200 nm NPs, a VMD flux of 3.2 kg/m2h and a LEPw of 34 psi were obtained with 99.99% salt rejection. Furthermore, it was observed that decreasing the membrane thickness would increase the portion of the finger-like layer in the membrane and reduce the spongy-like layer when hydrophilic NPs were used. Using continuous flow VMD, a flux of 3.1 kg/m2h was obtained with neat PVDF membranes, which was higher than the flux obtained by the static VMD with the same membrane at the same temperature and vacuum pressure. The fluxes of both static and continuous flow cells VMD increased with temperature. Furthermore, it was evident that the continuous flow cell VMD at 2 L per minute yielded higher flux than the static cell VMD at any given temperature, indicating strong effects of turbulence provided in the continuous flow cell VMD.

To improve the interfacial affinity and antifouling properties of polyphenylsulfone (PPSU) membrane, nano CuO/g-C

With the increase in worldwide consumption of nonrenewable energy resources (i.e., fossil fuels) and emission of toxic gases, it is our foremost concern to concentrate our research on sustainable and renewable energy. This motive paved the way to develop several renewable energy production and storage systems, like solar cells, supercapacitors, fuel cells, and lithium-ion batteries. These devices, with high specific power, long cycle life, portability, and ease of fabrication, have been able to secure worthy positions in the field of energy science and technology. Over the last decades, attempts have been taken to use nanostructured carbon-based materials, like graphene and carbon nanotubes (CNTs), with the aim of improving the efficiency of the abovementioned energy storage systems.

Disposed battery is a huge source of graphite in our environment. This graphite can be recycled by carrying out electrolysis at fixed voltage and the obtained product can be easily converted into graphene by the generation of graphene oxide (GO) as an intermediate using Hummer’s method. GO is converted into chemically reduced graphite oxide (CRGO) by sodium carbonate treatment and the material obtained is used as a filler in a drug (Ketorolac Tromethamine) loaded Hydroxypropyl methylcellulose (MC) matrix. The KT loaded CRGO\MC nanocomposite films is used to develop transdermal film for drug delivery where CRGO acts as a carrier. The recycled graphite (RGF), GO and CRGO materials has been characterized by Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Ultra-violet (UV) spectroscopy, Transmission Electron Microscopy (TEM), Thermo-Gravimetric Analysis (TGA) and Dynamic Light Scattering (DLS). KT loaded CRGO\MC nanocomposite films are characterized by TGA, XRD and moisture absorption properties analysis. The experimental result reveals the formation of successful exfoliated and stable KT loaded CRGO\MC transdermal film. XRD study reveals the crystalline nature of nanocomposite films. In vitro drug release studies showed that CRGO\MC based films can be used for controlled transdermal drug delivery applications.

Conducting polymer-noble metal nanocomposites have attracted considerable interest as electrochemical sensors because they provide better sensing responses to different analytes. We report the synthesis of rod like polypyrrole (PPY)-Ag nanocomposite using sodium cholate as soft-template for sensing nanomolar concentration of dopamine (DA). The nanocomposites were characterized by employing FT-IR, XRD, scanning and transmission electron microscopic analysis. Electrochemical impedance spectroscopy and cyclic voltammetry experiments were performed for electrochemical characterization of the PPY-Ag nanocomposite deposited on glassy carbon electrode (GCE). Electrochemical detection of DA using this nanocomposite deposited on GCE was done following linear sweep voltammetry. The PPY-Ag nanocomposite deposited electrode showed improved sensitivity value of 8.22 mAμM−1 for DA and a detection limit of 0.00005 μM. Biocompatibility assay of the developed PPY-Ag nanocomposites have exhibited less toxicity to mouse fibroblast cell even in comparison to that of PPY without silver. Antimicrobial property of the PPY-Ag nanocomposites towards E.coli and S. Aureus have also been observed.

Wetting phenomenon inside the pore is a significant obstacle hindering membrane distillation (MD) from being fully industrialized. Herein, a new equation is provided for the users, using the combination of computational fluid dynamics (CFD) and genetic programming (GP) tools for estimation of liquid entry pressure (LEP), a parameter closely related to pore wetting. CFD was applied to model the wetting process inside the pore during the gradual increase in feed pressure at different scenarios in which contact angle, pore radius and membrane thickness were changed. Afterwards, GP as an intelligent method was employed to provide a computer program estimating LEP in the whole ranges in which CFD modeling was carried out. Moreover, validation was done using experimental data and then the influence of effective parameters on LEP was studied. This work provides an explicit formula for estimation of LEP in a closer agreement with the experimental data in comparison to the Young-Laplace equation. In addition, the influence of the membrane thickness was added to the equation, providing a more realistic formula for LEP estimation.

Nanostructured conducting polymer provides higher surface area for analyte vapor sensing. This investigation aims to synthesize rod-like polypyrrole (PPY) silver nanocomposite tailored by sodium cholate surfactant as soft template for sensing of acetone vapor. During oxidative polymerization of pyrrole by ferric chloride Ag nanoparticle gets deposited on PPY by simultaneous reduction of silver nitrate. The crystal structure, surface morphology and nature of interfacial interactions between the two components of the prepared PPY-silver nanocomposite (PPY-Ag) are analyzed by standard characterization techniques. The Ag nanoparticles deposition on rod-like PPY increases with increasing silver nitrate concentration up to an optimum level. The PPY-Ag nanocomposites show chemiresistive type dynamic sensing responses toward methanol, ethanol and acetone vapor in a mixture with air. A comparative evaluation of typical vapor sensing parameters (% response, response time, recovery time, reproducibility, and selectivity) of PPY-Ag nanocomposite sensor obtained for different volatile organic compounds with those of the pristine PPY sensor is reported. Interestingly, the rod-like PPY-Ag nanocomposite is found to selectively sense acetone vapor showing better % response than that of the other analytes, viz., methanol, ethanol, propanol, water vapor and formaldehyde. The differences in their responses for the different analytes and the selectivity toward acetone vapor are established by considering the difference in their interactions with the nanocomposite.

Chitosan based proton exchange membranes (PEMs) has been synthesized by a facile solution casting strategy using two-dimensional exfoliated molybdenum disulfide (E-MoS2) nanosheets. The prepared PEMs are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field-emission scanning electron microscopy (FESEM) with Energy dispersive X-ray spectroscopy (EDX), water uptake, Thermogravimetric analysis (TGA), AC impedance spectroscopy and cyclic voltammetry. In comparison with pure chitosan membrane, E-MoS2 nanosheets incorporated membranes exhibit excellent water absorbing capacity, ion-exchange capacity and proton conductivity. Moreover, the changes in roughness of nanocomposite membranes is investigated by atomic force microscopy (AFM) and the results confirm that the E-MoS2 nanosheets content enhances the surface roughness as well as provide good mechanical and thermal resistivity to the chitosan/E-MoS2 membranes. Chitosan membranes with 0.75% E-MoS2 nanosheets demonstrated higher proton conductivity of 2.92 × 10-3 Scm-1 and membrane selectivity of 8.9 × 104 Scm-3 s with reduced methanol permeability of 3.28 × 10-8 cm2 s-1. Overall, results evidenced that the chitosan/E-MoS2 nanocomposite membranes will be an alternate to Nafion in direct methanol fuel cells (DMFCs).

A polyurethane nanohybrid has been prepared through the in situ polymerization of an aliphatic diisocyanate, ester polyol and a chain extender in the presence of two-dimensional platelets. Polymerization within the platelet galleries helps to intercalate, generate diverse nanostructure and improve the nano to macro scale self-assembly, which leads to a significant enhancement in the toughness and thermal stability of the nanohybrid in comparison to pure polyurethane. The extensive interactions, the reason for property enhancement, between nanoplatelets and polymer chains are revealed through spectroscopic measurements and thermal studies. The nanohybrid exhibits significant improvement in the shape memory phenomena (91% recovery) at the physiological temperature, which makes it suitable for many biomedical applications. The structural alteration, studied through temperature dependent small angle neutron scattering and X-ray diffraction, along with unique crystallization behavior have extensively revealed the special shape memory behavior of this nanohybrid and facilitated the understanding of the molecular flipping in the presence of nanoplatelets. Cell line studies and subsequent imaging testify that this nanohybrid is a superior biomaterial that is suitable for use in the biomedical arena. In vivo studies on albino rats exhibit the potential of the shape memory effect of the nanohybrid as a self-tightening suture in keyhole surgery by appropriately closing the lips of the wound through the recovery of the programmed shape at physiological temperature with faster healing of the wound and without the formation of any scar. Further, the improved biodegradable nature along with the rapid self-expanding ability of the nanohybrid at 37 °C make it appropriate for many biomedical applications including a self-expanding stent for occlusion recovery due to its tough and flexible nature.

A green, efficient synthesis of cadmium oxide decorated reduced graphene oxide nanocomposites (RGO/CdO) was prepared by one-step co-precipitation and hydrothermal method. Crystalline nature of the nanocomposites was characterized by X-ray diffraction analysis. To evaluate the structural morphology and particle size, high resolution transmission electron microscopy were used. X-ray photoelectron spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy techniques were employed to establish chemical structure of the nanocomposites and Atomic Force Microscopy was done to measure the thickness. The optical properties were evaluated by UV–visible absorption spectroscopy. Thermo-gravimetric analysis, BET surface area and zeta potential measurements were carried out to study the thermal and surface characteristics. The CdO nano-particles (NPs) decorated on RGO sheets exhibit better electrical conductivity compared to RGO. The antibacterial activity of the nanocomposites has also been monitored in different culture media imparting good potentiality than RGO.

Among other applications, metal-organic frameworks (MOFs) are slowly gaining grounds as fillers for desalination composite membranes. In this study, superhydrophobic poly(vinylidene fluoride) nanofibrous membranes were fabricated with MOF (iron 1,3,5-benzenetricarboxylate) loading of up to 5 wt % via electrospinning on a nonwoven substrate. To improve the attachment of nanofibers onto the substrate, a substrate pretreatment method called "solvent basing" was employed. The iron content in the nanofiber, measured by energy-dispersive X-ray spectroscopy, increased proportionally with the increase of the MOF concentration in the spinning dope, indicating a uniform distribution of MOF in the nanofiber. The water contact angle increased up to 138.06 ± 2.18° upon the incorporation of 5 wt % MOF, and a liquid entry pressure of 82.73 kPa could be maintained, making the membrane useful for direct contact membrane distillation experiments. The membrane was stable for the entire operating period of 5 h, exhibiting 2.87 kg/m

In this work, we report the development of a cross-linked bio-composite consisting of graphene oxide, potato starch, cross-linker glutaraldehyde and its application to adsorption of the industrial dye, methylene blue, from aqueous solution. The inexpensiveness, non-hazardous nature and easy bio-degradability are the major reasons for the selection of starch material as one of the components of the bio-composite. The bio-composite has been characterized by FTIR, SEM, XRD, particle size and zeta potential analysis. The FTIR analysis reveals the nature of the binding sites and surface morphology of the bio-composite can be understood through SEM. The auto-phase separability of the adsorbent i.e., the precipitation of the adsorbent without any mechanical means is another factor which makes this particular material very attractive as an adsorbent. Parameters like adsorbent dosage, pH, temperature, rotation speed and salt concentration have been varied to find out the suitable dye adsorption conditions. Furthermore, the time dependence of adsorption process has been analyzed using pseudo-first and pseudo-second order kinetics. The adsorption isotherms have been constructed to suggest convincing mechanistic pathway for this adsorption process. Finally, desorption studies have been successfully performed in 3 cycles, establishing the reusability of the material, which should allow the adsorbent to be economically promising for practical application in wastewater treatment.

Effects of hydrophilic silica nanoparticles and Non-Woven Fabric (NWF) backing material on the properties and performance of the Polyvinylidene Fluoride (PVDF) membrane have been studied in this work. The nanocomposite membranes were prepared by the phase inversion method and characterized in terms of surface pore size, cross-sectional morphology, thickness, porosity, surface roughness and hydrophobicity. The fabricated membranes were subjected to Vacuum Membrane Distillation (VMD) experiments and their performance was evaluated through measuring the pure water flux and salt rejection. According to the results, effects of the hydrophilic nano-additives and NWF polyester enabled much higher VMD flux than the neat PVDF membrane when an appropriate amount of the nano-filler was added, possibly due to increase in the surface pore size and the reduction of the sponge-like layer thickness. The supported nanocomposite membranes possessed appropriate Liquid Entry Pressure (LEP w ) and mechanical strength, which make the membrane applicable in VMD process. When 7.0 wt.% of the silica nanoparticles was incorporated in a NWF supported membrane, the pure water flux became 12749.6 g/m 2 h at feed temperature of 27.5 °C and permeate side pressure of 1.2 kPa, representing a 2456% increase from the neat PVDF membrane. Almost complete NaCl rejection was also achieved when tested with 35 g/L NaCl aqueous solution.

Packaging film that possess antimicrobial activity is one of the ground-breaking concepts in food packaging. The main object of this work was to develop nontoxic nanocomposite films with good antimicrobial properties. Cellulose acetate (CA), polyethylene glycol (PEG) and cetyltrimethylammonium bromide (CTAB) modified montmorillonite (OMMT) were used to prepare the nanocomposite films. OMMT is characterized using X-ray diffraction (XRD) and Fourier transform infrared analysis. The films composed of 20 wt% PEG in a CA matrix (CP20) gave optimum results in terms of mechanical properties. OMMT (1, 3 and 5 wt%) was incorporated into the CP20 matrix to prepare the nanocomposites. XRD and transmission electron microscopy analysis showed that the nanocomposites are intercalated in nature. 3 wt% OMMT loaded nanocomposite gave the best results in terms of mechanical and barrier properties. The storage modulus and thermal stability of the nanocomposites increase with the increasing concentration of OMMT from 1–5 wt%. Optical clarity of the nanocomposites is not much affected in the visible region with different loadings of OMMT. These nanocomposites possess good antimicrobial activity as well as showing no toxicity towards human blood, so can be used as active packaging material.

Lac, a natural resin, is used to synthesize gold nanoparticles (AuNPs). This biodegradable natural fluorophore contains different laccaic acids, which consist of mainly the derivatives of red anthraquinone dye. For the first time, we report an in situ green synthesis of fluorophore stabilized AuNPs. The synthesis of AuNPs is monitored using both excitation and emission spectrophotometry, which gives us an idea about the progress of the reaction during nanoparticles synthesis. The size of the synthesized nanoparticles is visualised by TEM. The TEM data of the AuNPs are also correlated using DLS measurements, and the zeta potential values establish the stability of the nanoparticles. The FTIR spectra indicate the different groups present in lac and also their probable interactions during the reducing-cum-stabilizing process with the nanoparticles. The AuNPs are crystalline in nature, which is established by XRD analysis. The lac extract also binds with calf thymus DNA and forms a ground state complex, which is established spectrophotometrically by UV-Vis, as well as fluorimetrically. The antimicrobial tests against bacteria and the antitoxicity study have revealed that the lac stabilized AuNPs are safe and non-toxic, having the potential for clinical applications in the medical field.

Films based on methylcellulose (MC) and pectin (PEC) of different ratios were prepared. MC/PEC (90:10) (MP10) gave the best results in terms of mechanical properties. Sodium montmorillonite (MMT) (1, 3 and 5 wt%) was incorporated in the MP10 matrix. The resulting films were characterized by X-ray diffraction and transmission electron microscopy, and it was found that nanocomposites were intercalated in nature. Mechanical studies established that addition of 3 wt% MMT gave best results in terms of mechanical properties. However, thermo-gravimetric and dynamic mechanical analysis proved that decomposition and glass transition temperature increased with increasing MMT concentration from 1 to 5 wt%. It was also observed that moisture absorption and water vapor permeability studies gave best result in the case of 3 wt% MMT. Optical clarity of the nanocomposite films was not much affected with loading of MMT. In vitro drug release studies showed that MC/PEC/MMT based films can be used for controlled transdermal drug delivery applications.

Bile salts carry out a vital bioactive responsibility among the various physiologically important molecules. The use of bile acids and their conjugates in nanoscience is a novel idea, which opens up fascinating prospects and gives rise to various versatile properties. Sodium cholate, a biosurfactant which is environmentally safe, has been used to reduce and stabilize silver nitrate solution. The silver nanostructures thus produced are crystalline and anisotropic in nature and show different types of particle shapes and sizes depending on the reaction conditions including star and wire shapes which have not been reported earlier, by simply varying the reaction conditions. The silver precursor concentration and the ratio of sodium cholate to silver precursor were the key factors which controlled the morphosynthesis. The formation of the silver NPs was monitored using UV-vis spectrophotometry. The transmission electron microscopy (TEM) technique was used to study the morphology of the synthesized NPs. Fourier transform infrared (FT-IR) spectroscopy was used to identify the interaction of sodium cholate with the synthesized NP. The possible mechanistic role of sodium cholate in the reduction and stabilization of silver nanoparticles (Ag NPs) has also been discussed. The obtained Ag NPs exhibit antibacterial and anticancerous activities. The present study also explores the cytotoxic role of Ag NPs in KG-1A (human acute myeloid leukemia) and K562 (human chronic myeloid leukemia) cell lines.

Amine-functionalized graphene has been chemically tagged within long-chain polyurethane molecules, using graphene as a chain extender to prepare a nanohybrid, and its novelty has been explored by comparing its properties with those of physically dispersed functionalized graphene in polyurethane based on di-ol as a chain extender. Chemical tagging has been confirmed through NMR studies and the nature of the interaction between the polymer matrix and graphene (nanofiller) is stronger in the chemically tagged nanohybrid compared to a nanohybrid prepared through physical mixture, as revealed from FTIR, UV-visible and PL spectroscopic measurement. A homogeneous dispersion of graphene platelets is achieved through a chemically tagged nanohybrid as against the agglomerated nanostructure found in a physically mixed nanohybrid. Enhancement of thermal properties and toughening of the nanohybrids is observed, whose extent is significantly higher in the chemically tagged nanohybrid due to greater interactions between the components and the uniform dispersion of nanofiller. Graphene-induced self-assembly from the nanometer scale to the micron level (step by step) was investigated through X-ray diffraction, small angle neutron scattering, atomic force microscopy and optical images in the order of nanometer, tens of nanometer, hundreds of nanometer and micron size, respectively. The effects of self-assembly on drug release and the biocompatible nature of the nanohybrids were monitored using HeLa cells, looking at cell viability, cell adhesion and fluorescence imaging. Significant sustained release of an anti-cancer drug was obtained using the chemically tagged nanohybrid and understanding gained of its kinetic behavior and mechanism. The greater biocompatibility of the chemically tagged nanohybrid was revealed through cell adhesion and fluorescence imaging, demonstrating a superior biomaterial which delivers the anti-cancer drug in a sustained manner. Hence, the developed nanohybrid is a potential biomaterial for drug delivery and tissue engineering.

The need to develop innovative types of hemodialysis membranes stems from the increasing incidence of renal failure and the abysmally low availability of healthy kidneys for transplantation. We aim to improve the efficiency and biocompatibility of hemodialysis membranes by the incorporation of functionalized multi-walled carbon nanotubes/polyvinyl pyrrolidone (f-MWCNTs/PVP) composites into the polyetherimide membrane matrix. The mixed matrix membranes (MMMs) were characterized by Fourier transform infrared spectroscopy, porosity, thermo-gravimetric analysis, etc. The change in cross-sectional and top surface morphology of the flat sheet mixed matrix membranes could be observed using scanning electron microscopy and atomic force microscopy. The improvement in the hydrophilicity was confirmed by the smaller water contact angle values observed. Membranes with higher concentration of the f-MWCNTs exhibited significant creatinine adsorption from model solutions in static conditions. These membranes when challenged with model protein solutions (albumin, globulin, and fibrinogen), displayed a significant depression in the quantity of proteins adsorbed, which is an indication of enhanced biocompatibility. Moreover, the membranes also prolonged blood coagulation time, suppressed attachment/activation of platelets and prevented hemolysis of the contacted red blood cells. The improvement of Chang Liver cell viability evidenced by formazan adsorption and the double cell staining technique is an indication of the cytocompatibility of these MMMs. Hollow fiber membranes of the same composition were prepared and potted into a module so as to create an effective surface area of 0.7 m2. The ultrafiltration coefficient, human serum albumin retention, was evaluated and found to be superior for these prepared membrane modules. These mixed matrix hollow fiber membranes demonstrated a greater removal of uremic toxins due to adsorption as well as diffusion. These membranes should be further investigated as potential blood purification systems.

This study demonstrates the electronic applications of graphene synthesized from the graphite electrode of waste dry cell zinc–carbon batteries. Graphite powder [G (R)] is successfully recovered from the graphite electrode of waste batteries by acid treatment and used as starting material for synthesis of graphene oxide (GO) following Hummers method. Finally, reduced graphene oxide (RGO) was obtained from the chemical reduction of GO by hydrazine hydrate. RGO thus obtained was characterized by X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, UV-vis absorption spectroscopy, dynamic light scattering, energy dispersive X-ray spectra and transmission electron microscopy to get detailed information about the structure and morphology of the RGO. All the above characterization results confirmed the restoration of sp2 conjugation and removal of functional groups after the reduction of GO and also the sheet like morphology of RGO. The surface charge and stability of RGO in an aqueous medium are examined by measuring zeta potential. An electrochemical study demonstrated that, at different sweep rates, the current is the highest for RGO and lowest for GO and the current increases with an increasing sweep rate for all materials. The loop area of all the samples at the 100 mV s−1 sweep rate is the highest. The galvanostatic charging/discharging measurements have also been performed for both the GO and RGO samples at a current density of 1 mA g−1. Electro-conductivity measurement shows that RGO has higher conductivity than GO due to the restoration of the sp2 structure. The current voltage (I–V) characteristics show a non-linear behavior of GO and the ohmic nature of RGO.

Permeability characteristics of the anti-hypertensive drug, diltiazem hydrochloride, from uncross-linked and cross-linked methylcellulose (MC)/graphene oxide (GO) rate controlling membranes (RCMs) were investigated. The MC/GO membranes were cross-linked with different concentrations of glutaraldehyde (GLA) to examine the effect of cross-linking on the permeability characteristics. The ATR-FTIR spectra, along with solubility resistance, swelling studies, the molar mass between cross-links, and moisture absorption of cross-linked RCMs over the uncross-linked RCM confirmed the cross-linking between MC and GO. The cross sectional view of cross-linked and uncross-linked RCMs, as observed by SEM, showed that the porous and fibrillose structure of the uncross-linked RCM was disrupted after cross-linking. The cross-linked RCMs showed improved mechanical and thermal properties compared to the uncross-linked RCMs. In vitro and ex vivo drug release was found to depend on the concentration of the cross-linker, which suggests that drug delivery is controlled by the cross-link density of RCM.

Through nanochannels are fabricated in poly(vinylidene fluoride-co-hexafluoro propylene) films by bombarding swift heavy ions ( SHI ) of energy 80 MeV and thereby creating latent tracks in the ion passage followed by chemical etching of the amorphous track. The dimension of the nanochannel is varied from 34 to 65 nm using different fluences and by dispersing organically modified nanoclay in polymer matrix. The nanochannels are grafted with polystyrene using the free radicals caused by SHI irradiation followed by their sulfonation. Nanoclay nucleates piezoelectric β -phase in copolymer whose extent gets enhanced after irradiation, grafting and sulfonation leading to a better material. The efficiency of functionalized nanochannel conduction is studied through dc conductivity of the bulk film in the semiconducting range against the insulating nature of the pristine copolymer. Current-voltage (I–V) characteristic of the membrane exhibits strong fluence dependency and shows superior conduction in functionalized nanohybrid. Proton conductivity of the functionalized nanohybrid is 6.2 × 10 −2 S cm −1 , while methanol permeability drastically reduces indicating higher values of the selective parameter of the developed membrane as compared to Nafion. Membrane electrode assembly studies of functionalized nanohybrid show 0.63 V as open circuit voltage leading to power density of 30.8 mW/cm 2 , considerably higher than the functionalized copolymer.

In this work a novel method to evaluate the partial pore wetting of gas absorption membranes is proposed. The method consists of two approaches, one by energy-dispersive X-ray spectrometry (EDX), and the other by calculating the mass transfer resistances from the gas and liquid phase in the pore, using the parameter obtained by He gas permeation experiments. For this purpose, hollow fibers were spun from polyetherimide (PEI) and polyethersulfone (PES). As well, the lumen of a PEI hollow fiber was coated with silicone rubber. The hollow fibers were then characterized by He gas permeation experiments, critical entry pressure of water (CEPw), contact angle, scanning electron microscopy (SEM) and EDX. The hollow fibers were then subjected to CO2 gas absorption using aqueous NaCl solution as absorbent. After drying the hollow fiber was subjected to the EDX analysis. The cross-sectional profile of Na and Cl content in the hollow fiber revealed that the pores of the PES hollow fibers were partially wetted, particularly at the pore inlet. Calculation of mass transfer resistances, on the other hand, revealed that the resistance came from gas phase in most hollow fibers, except for the PES hollow fiber where the liquid phase contribution was significant. Silicone rubber coating of the PEI hollow fiber increased the surface hydrophobicity and reduced the pore wetting considerably. Thus, it was concluded that the proposed method can be used as a powerful tool to investigate the pore wetting for many membrane contactor applications.

Amphiphilic triblock copolymer (Pluronic F127) was used as a macromolecular additive to modify the surface of poly(ether imide) (PEI) ultrafiltration (UF) membranes with additive contents from 0 to...

Polyvinylidene fluoride (PVDF)/SiO2 flat sheet composite membranes were prepared for vacuum membrane distillation (VMD) by the phase inversion immersion precipitation process. The effect of blending superhydrophobic SiO2 nanoparticles into the PVDF dope solution was studied. The concentration of the nanoparticles in the dope solution was varied at different wt.% (1, 2, 4, 6, 7, 8 and 10 wt.%). The prepared membranes were characterized by scanning electron microscopy, water contact angle, porosity, liquid entry pressure of water, Fourier transformed infrared spectroscopy, and VMD at feed temperature of 27 °C. The nanoparticles enhanced the membrane performance through a reduction in the sponge-like layer thickness and an increase in surface pore size, leading to increased vapour flux with a maximum at 7 wt.%. The salt rejection was greater than 99.98% when a 35 g/L NaCl solution was used as feed. At this concentration, the smallest thickness of the sponge-like layer and largest macro-voids were also achieved. Beyond 7 wt.%, the sponge-like layer became predominant and the flux was reduced. With a vapour flux increase of up to 4 times (from 0.7 to 2.9 kg/m2 h) when compared to the neat membrane, this nanocomposite membrane could be of great potential in the desalination process through VMD.

Membranes were prepared from three poly(vinylidene fluoride) (PVDF) of different molecular weights by the phase inversion process. The membranes were characterized by scanning electron microscopy, gas permeation tests, contact angle (CA) and liquid entry pressure of water (LEPw) measurements, and further subjected to the test of flux for vacuum membrane distillation (VMD) in a scenario that is applicable for cooling processes. The results showed that the increase in PVDF molecular weight increased the viscosity and thermodynamic instability of the casting solution significantly. Regarding characterization and performance testing, the membrane prepared from the intermediate molecular weight of Kynar® MG 15 polymer showed the highest VMD flux (325 g/m2 h) at the feed temperature of 27 °C and the lowest LEPw (622 kPa) due to the largest pore size (49.8 nm) observed among all the tested membranes. The highest flux of this particular membrane seems also due to the thinnest finger-like and sponge-like layer.

Hemodialysis is one of the most commonly used treatments for patients suffering from irrecoverable kidney damage. In our present work, we investigate poly(ether imide) (PEI) mixed matrix membranes (MMMs) as a potential candidate for hemodialysis applications due to their efficient clearance and high biocompatibility. Graphene oxide (GO) was synthesized by the modified Hummers’ method and was then confirmed by X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and high-resolution transmission electron microscopy. The GO-polyvinylpyrrolidone nanocomposite incorporated PEI MMMs were fabricated by a semiautomatic casting unit using the nonsolvent induced phase separation technique. The effect of the nanocomposite loading ratio was evaluated by water content, ultrafiltration rate, and porosity, which were all found to increase as the nanocomposite content increased. Cross-sectional and top surface morphology was visualized using scanning electron microscopy and atomic ...

Separation using selective polymeric membranes has been well-established as an energy-efficient and cost-effective technology in water treatment and many other applications involving aqueous solutions. However, limited chemical, thermal, and mechanical resistances besides their tendency to fouling and inadequate pure water flux may often restrict their applications. To this end, inorganic materials as additives have been demonstrated to be able to enhance chemical, thermal, and fouling membrane resistances, which demonstrate their great potential for developing novel membranes by using them as additives in polymer matrices. Considering the excellent characteristics of the nanosized particles, this study reviews the effects of inorganic nano-additives on properties and performance of polymer/nanoparticle composite membranes. It has been demonstrated that using nanomaterials in a polymer matrix could enhance the mechanical strength and stiffness, wettability, selectivity, water permeability, and antifouling...

In this study, composite membranes of hydrophilic CuO and CaCO3 nanoparticles and polyvinylidene fluoride (PVDF) were developed by phase inversion method. The fabricated membranes were subjected to different characterizations including morphology study, pore size, porosity, and thickness measurement, wettability and surface roughness analysis. The membrane performance was examined in terms of pure water flux in vacuum membrane distillation (VMD), salt rejection, and liquid entry pressure of water (LEPw). It was found that the membrane performance was optimized when 1.0 to 2.0 wt.% of CuO nanoparticles were embedded into the PVDF matrix via enhancing the membrane structure through enlarging surface pores and thickening the finger-like layer (in other words, thinning of the sponge-like layer). As a result, flux increased by 153.4% at the feed temperature of 27.5 °C and vacuum pressure of 1.2 kPa, when 2.0 wt.% of the CuO nanoparticles were embedded in PVDF. Membrane selectivity did not drop as a result of the CuO nanoparticles incorporation and was more than 99.99%. All the nanocomposite membranes showed reasonable contact angle and LEPw, which proved appropriateness of the fabricated membranes for VMD application. Regarding the type of hydrophilic nanomaterials, CuO demonstrated better performance than CaCO3 in terms of membrane permeability improvement.

The structure and performance of modified poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-co-HFP) ultra-filtration membranes prepared from casting solutions with different concentrations of poly(vinyl pyrrolidone) (PVP) were investigated in this study. Membrane properties were studied in terms of membrane compaction, pure water flux (PWF), water content (WC), membrane hydraulic resistance (Rm), protein rejection, molecular weight cut-off (MWCO), average pore size, and porosity. PWF, WC, and thermal stability of the blend membranes increased whereas the crystalline nature and mechanical strength of the blend membranes decreased when PVP additive concentration was increased. The contact angle (CA) decreased as the PVP concentration increased in the casting solution, which indicates that the hydro-philicity of the surface increased upon addition of PVP. The average pore size and porosity of the PVdF-co-HFP membrane increased to 42.82 A and 25.12%, respectively, when 7.5 wt% PVP was blended in the casting solution. The MWCO increased from 20 to 45 kDa with an increase in PVP concentration from 0 to 7.5 wt%. The protein separation study revealed that the rejection increased as the protein molecular weight increased. The PVdF-co-HFP/PVP blended membrane prepared from a 7.5 wt% PVP solution had a maximum flux recovery ratio of 74.3%, which explains its better antifouling properties as compared to the neat PVdF-co-HFP membrane. POLYM. ENG. SCI., 55:2482–2492, 2015. © 2015 Society of Plastics Engineers

Blend membranes comprising sulfonated poly (phenylene ether ether sulfone) (SPEES) - charged surface modifying macromolecules (cSMMs) were fabricated as an alternative proton exchange membrane (PEM) for H2/O2 fuel cell applications. Prepared membranes were characterized by determining the ion exchange capacity, water uptake, proton conductivity, oxidative stability and dimensional stability. The water uptake of SPEES/cSMM blended membrane was found to be higher than that of the pristine SPEES and the Nafion 117 membranes. Proton conductivity of the blend membranes is in the range of 10−3 to 10−2 S/cm. The conductivity of the prepared membranes increases with temperature, in particular, the poly (propylene glycol) – hydroxy benzene sulfonate (PPG-HBS) blended SPEES membrane shows rise in conductivities from 1.61 × 10−2 S/cm (25 °C) to 5.22 × 10−2 S/cm (80 °C). Surface morphology of the membranes was investigated by tapping mode atomic force microscopy (AFM), which indicates that the nodule size and surface roughness are increased by the incorporation of cSMM into the SPEES matrix. Surface modified blended membranes exhibited excellent thermal stability and acceptable dimension stability in 80 °C, which implies that the SPEES/cSMM blended membranes are promising materials for PEMFC application.

Functionalization of poly(vinylidene fluoride) (PVDF) nanohybrid has been performed in template system using two-dimensional layered silicate and superior fuel cell membrane has been demonstrated. Sulfonation of nanohybrid has been carried out at control condition to maintain the mechanical stiffness and toughness of the membrane using chlorosulfonic acid and the results have been compared with pure PVDF. The sulfonation and its relative extent have been confirmed through NMR, FTIR and UV–vis measurements showing greater degree of functionalization in nanohybrid which arises from the specific arrangement of polymer chains on top of nanoplatelets. The structural change over from common crystallized form α- to piezoelectric β-phase in nanohybrid has been established and the amount of β-phase has been enhanced after sulfonation as evident from deconvoluted XRD patterns and DSC measurement. A plausible mechanism has been proposed for this improvement which led to the formation of smart membrane. Essential criteria of an ideal membrane have been verified through high water uptake, low permeability and hydrophilic nature by measuring contact angle. The molecular level clustering due to the attachment of sulfonate group in main chain has been explored which in turn explain the higher barrier property both for gas and liquid (fuel). Proton conductivity of functionalized nanohybrid has been found to be quite high along with significantly low methanol cross over as compared to standard Nafion membrane. I–V characteristics of the nanohybrid membrane show high potential at low current density with considerably lower value of slope. Membrane electrode assembly using functionalized nanohybrid exhibit significantly high value of current density and prove its worth for superior fuel cell membrane using common thermoplastic polymer.

In this study, polyetherimide (PEI) ultrafiltration (UF) membranes were fabricated by incorporating different amounts of hydrophilic polyvinylpyrrolidone (PVP) via the phase inversion technique. The PEI/PVP blended membrane showed the highest pure water flux (147.1 L m–2 h–1), water content (70.2%), and surface energy (112.1 mN/m) when the 8 wt % of PVP was blended into the base polymer PEI. This particular membrane, designated as PVP 8, also showed the lowest contact angle (56.1°), hydraulic resistance (2.2 kPa/(L m–2 h–1)), and shrinkage ratio (4.3%). The addition of PVP has reduced the tensile strength of the PEI membrane because of the decrease in rigidity. The UF experiments with the following proteins, bovine serum albumin (BSA), egg albumin (EA), pepsin, and trypsin, had experienced a decrease in protein rejection whereas permeate flux increased by increasing PVP loading. The BSA adsorption experiment revealed that the adsorbed amount of BSA on the surface of the membrane was notably decreased from...

N-phthaloyl chitosan (NPHCs), which could be dissolved in various organic solvents, is synthesized for the modification of poly (ether imide) (PEI) ultrafiltration membrane. Blend membrane with 2 wt% NPHCs exhibited higher pure water flux (112.2 l m−2 h−1), higher water content (63.4%) and lower hydraulic resistance (3 kPa/l m−2 h−1). The top surface morphology of the control PEI membrane changed from a dense surface to visible pores with the increase in NPHCs concentration. The surface roughness of PEI membranes increased with an increase in NPHCs concentration in the casting solution. Application studies were carried out to find the rejection and permeate flux of proteins such as bovine serum albumin (BSA), egg albumin (EA), pepsin and trypsin and toxic heavy metal ions such as Cr(III), Zn(II), Cd(II) and Pb(II). The result shows that the flux and separation performances are dependent upon the content of NPHCs. Furthermore, the blend membranes were subjected to the determination of pore statistics and MWCO. It was found that the blending of NPHCs into the PEI membrane had a visible effect upon MWCO and pore size. The significant effect of hydrophilicity of NPHCs on the fouling of PEI/NPHCs blend membranes by BSA was also discussed. It was found that the blend membranes with 2 wt% NPHCs content had a higher FRR (88.6%), higher reversible fouling (23.7%) and lower irreversible fouling (11.4%) which explained their improved antifouling properties. Thus, the modified chitosan proved to play an important role in the improvement of UF membrane performance.

Polymeric nanocomposites embedded with nontoxic antimicrobial agents have recently gained potential industrial significance, mainly for their applicability to preserve food quality and ensure safety. In this study, a poly(butylene adipate-co-terephthalate) (PBAT)/organoclay (CMMT) based nanocomposite film doped with sodium benzoate (SB) as antimicrobial agent was prepared by a solution mixing process. A homogenous dispersion of organoclay (cetyltrimethylammonium-modified montmorillonite [CMMT]) in PBAT matrix was observed by X-ray diffraction and transmission electron microscopy. PBAT/CMMT nanocomposite film showed higher barrier properties against water and methanol vapor compared to the PBAT film. The release of SB from PBAT and its nanocomposite film was measured and the relevant data were fitted to the Weibull model. The higher values of Weibull's shape factor and scale parameter as corroborated by experimental findings indicated faster rate of SB release from PBAT/CMMT/SB nanocomposite film, when compared to the pristine PBAT film. Bacterial inhibition studies were accomplished against 2 food pathogenic bacteria, Bacillus subtilis and Staphylococcus aureus, by determining the zone of inhibition and corresponding growth profiles. Both bacterial inhibition studies and growth profiles established that PBAT/CMMT/SB demonstrated better antimicrobial activity than PBAT/SB film. Therefore, PBAT/CMMT/SB nanocomposite film can be used for food packaging application as it showed good barrier properties and antimicrobial activity against food pathogenic bacteria. Practical Application Current investigations revealed that PBAT/CMMT/SB nanocomposite film exhibits good barrier properties and antimicrobial activity against food pathogenic bacteria. The PBAT/CMMT/SB nanocomposite film may be a better alternative than pure PBAT film for food packaging application.

Fuel cells (FCs) have evolved as a potential alternative energy harnessing device, with direct methanol fuel cell (DMFC) as one of the front-runners. Although it has achieved significant progress, and is currently getting available in the commercial market; however, from a broader perspective, DMFCs, like most other devices, suffer from certain critical drawbacks. This, in turn, demands considerable progress to be made in order to realize ultimate commercialization, i.e., cheap, reliable, durable, and portable DMFCs with easily accessible fuel. In this respect, one important area of real concern is the DMFC electrodes, consisting of catalysts and catalyst-supporting matrices. Sluggish reaction rates and use of highly expensive and scarce catalysts are two critical drawbacks. Conducting polymers (CPs) have found extensive use in the fabrication of these matrices and have resulted in better dispersion, distribution and anchoring of catalysts, which is important to enhance their reaction efficiencies. This r...

Sulfonated poly(ether imide) (SPEI) and charged surface modifying macromolecules (cSMM) were synthesized, characterized and blended into the casting solution of poly (ether imide) (PEI) with different compositions to develop surface modified ultra-filtration (UF) membranes by means of improved hydrophilicity. The membranes were prepared by a phase inversion technique and subjected to characterization experiments such as water permeation tests, equilibrium water content (WC), membrane hydraulic resistance (Rm) and protein rejection. Among others, a blend membrane containing 20 wt% SPEI and 5 wt% cSMM in PEI (called M12) exhibited the highest water permeation (440.6 L m−2 h−1 at 345 kPa), highest WC (86.3%) and lowest Rm (0.7 kPa/L m−2 h−1). The M12 membrane also exhibited the highest fluxes of 364.1 L m−2 h−1 and 230.3 L m−2 h−1 (at 345 kPa) with rejections of 31.3% and 62.1%, respectively, when the feed was aqueous trypsin and bovine serum albumin solution (1000 ppm). The difference in contact angle between the top and bottom surface confirmed surface migration of cSMM to the membrane top surface. SEM, AFM and tensile strength measurement revealed that the surface became more porous and rougher, and the mechanical strength was lowered by the blending of SPEI and addition of cSMM. That the M12 membrane achieved a lower internal fouling of 6% and 3.8% and higher flux recovery ratio (FRR) of 94% and 96.2% after UF of trypsin and bovine serum albumin solution explained its better antifouling properties as compared to a pristine PEI membrane.

The charged surface modifying macromolecule (cSMM) was blended into the casting solution of poly(ether imide) (PEI) to prepare surface modified ultrafiltration membranes by phase inversion technique. The separation of proteins including bovine serum albumin, egg albumin, pepsin and trypsin was investigated by the fabricated membranes. On increasing cSMM content, solute rejection decreases whereas membrane flux increases. The pore size and surface porosity of the 5 wt% cSMM blend PEI membranes increases to 41.4 Å and 14.8%, respectively. Similarly, the molecular weight cut-off of the membranes ranged from 20 to 45 kDa, depending on the various compositions of the prepared membranes. The toxic heavy metal ions Cu(II), Cr(III), Zn(II) and Pb(II) from aqueous solutions were subjected to rejection by the prepared blended membrane with various concentration of polyethyleneimine (PETIM) as water soluble polymeric ligand. It was found that the rejection behavior of metal ion depends on the PETIM concentration and the stability complexation of metal ion with ligand.

A solid super desiccant was developed based on the concept of impregnating a super liquid hygroscopic agent in a superabsorbent polymer to take advantage of the vast vapour absorption capacity of the hygroscopic agent and the liquid withholding capacity of the superabsorbent polymer. The maximum hygroscopic salt loading was determined based on different salt concentrations in sodium polyacrylate. The newly developed desiccant showed a vapor absorption capacity of 276 ± 20%, which is superior in comparison to that of conventional solid desiccants such as silica gel, activated alumina and molecular sieves. Thus they have great potential in applications requiring solid desiccants such as desiccant cooling, air conditioning, storage of moisture sensitive materials, and dehydration of natural gas.

Through channels in thin polymer/nanohybrid films have been made by irradiating with high energy swift heavy ions (SHI) followed by selective chemical etching of the amorphous zone in the latent track created by SHI during the bombardment. The average size of the nanochannels (30–65 nm) was controlled by varying the fluence of SHI along with the nanohybrid preparation of the polymer, by dispersing a few percent of two-dimensional nanoclay in the matrix. Grafting was applied within the nanochannels through polymerization of conducting poly(3-hexyl thiophene) which was further functionalized to make the channels ion conducting. Nanoclay alters the crystalline phase to the piezoelectric all-trans β-phase in the nanohybrid whose extent has increased further after irradiation, grafting and sulphonation. Structural alteration has also been reflected in its thermal behavior (similar melting behavior in the pure polymer against the considerably higher melting point in the functionalized nanohybrid). The bulk dc conductivity of the functionalized membrane increased 13 orders of magnitude compared to the unirradiated specimens and activation energies also increased for the functionalized hybrid membrane (20 and 32 kJ mol−1 for the functionalized pure polymer and its nanohybrid, respectively) suggesting better stability of the functionalized membranes at higher temperature. Water uptake and proton conductivities of the functionalized hybrid membranes are similar to those of the standard Nafion membrane while the higher selectivity parameter along with significantly lower methanol permeability of the functionalized hybrid membrane strongly suggests that it is a better membrane for fuel cell applications. A membrane electrode assembly has been prepared to measure the performance of direct methanol fuel cells indicating a significantly higher value of power density of the developed functionalized hybrid membranes.

Our research is devoted to developing a methylcellulose (MC) based in situ gelling ophthalmic formulation using pilocarpine hydrochloride as a model drug, containing different proportions of i (iota)-carrageenan and potassium chloride. This study will evaluate the utility of the proposed formulation to be a substitute for traditional eye drops. Use of both i-carrageenan and potassium chloride of definite wt% effectively reduces the gel temperature of the virgin MC solution from 60 °C to 33.5 °C which is below physiological temperature. The conventional methods like test tube tilting, and viscosity measurements are used to determine the gelation temperature while the gels are subjected to swelling as well as a gel dissolution study. Subsequently, the outcome from in vitro and in vivo studies confirms that the present system may be a better alternative compared to conventional eye drops.