Nano silver particles with an average mean crystallite size of between 10 and 12 nm were synthesized from different molecular weights of poly(ethylene glycol) as a stabilizing agents, through solid state oxidation of silver nitrate using a higher energy planetary ball mill. Ultraviolet-Visible spectra were used to confirm the synthesis of nano silver particles. The surface plasmon resonance bands were observed around 410 nm. Fourier transformed infrared spectrum, X-ray diffraction, and transmission electronic microscopy techniques were used to characterize the nano silver particles synthesized. Thermal stability was determined using thermogravimetic analysis and the elemental composition of the sample was determined by energy dispersive X-ray analysis. The nano silver particles synthesized, exhibited very good antibacterial activity against Gram-positive bacteria (Bacillus) and Gram-negative bacteria (Pseudomonas aeruginosa). Based on the obtained results, it was additionally explored that the size and the stabilization of the nano silver particles synthesized, strongly depend on the molecular weight of poly(ethylene glycol).

SYNOPSISGraft copolymers of carboxymethyl cellulose and starch with polyacrylamide have been synthesized by grafting acrylamide onto carboxymethyl cellulose and starch, respectively, using a ceric-ion-initiated solution polymerization technique. These graft copolymers have been tested for their drag-reduction effectiveness, shear stability, and biodegradability. It has been shown that grafting enhances the drag-reduction effectiveness and shear stability and also that these factors are very much dependent on the length and number of grafts in the molecule. None of the graft copolymer solutions shows any microbial degradation up to 10 days. I NTRO DUCT10 NThe polymeric drag reduction has shown much promise in reducing the energy requirement of crude oil and water transport through pipes. The watersoluble flexible synthetic polymers and rigid polymers from natural resources reduce drag in a turbulent flow of water. The flexible polymers like poly (ethylene oxide) and polyacrylamide cause maximum drag reduction ( = 80% ) in turbulent pipe flows at the concentration of a few 10s of ppm but are easily shear degradable. On the other hand, rigid polysaccharides like guar gum, xanthan gum, carboxymethyl cellulose, and synthetic polymer [ poly (vinyl alcohol) ] are fairly shear stable but are relatively poor drag-reducing agents. They require much higher concentrations ( 5 500 ppm) to cause maximum drag reduction ( = 60% ) . Recently it has been shown'-4 in the authors' laboratory that by grafting polyacrylamide chains on guar gum and xanthan gum it is possible to synthesize graft copolymers that have higher drag-reduction effectiveness than do the backbone polymers and that possess shear stability comparable to that of the backbone

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Sodium carboxymethylcellulose/poly (vinyl alcohol) mixed matrix membranes filled with different amounts 4A zeolite (0,5,10,15, and 20 wt %) were prepared by solution casting method. Prepared membranes were crosslinked with GA and used for pervaporation dehydration of isopropyl alcohol of different feed mixtures at 35 C. On increment in zeolite content in the membrane it was found the improvement in the performance of the membrane, due to its hydrophilic nature and molecular sieving effect in addition to its favorable interaction with hydrophilic sodium carboxymethylcellulose and polyvinyl alcohol. The structure and chemical constituents of the MMM's were investigated by attenuated total reflectance Fourier transform infrared spectroscopy. Thermal stability of the membranes was assessed by DSC and TGA techniques. Crystallinity of the membranes was assessed using X-ray diffraction, and the morphological properties were assessed by scanning electron microscopy. Mechanical properties were also carried out to determine the tensile strength and % of elongation at break using universal testing machine. It was found that the mechanical strength increases with increase in the zeolite content upto 15 wt % of zeolite with an optimum tensile strength of 113.31 N/mm 2 . Pervaporation was carried out to asses the membrane performance, the highest flux and selectivity obtained is 0.584 kg/m 2 /h and 6945 for NaCMCA20 and NaCMCA15, respectively, for a feed composition containing 17.5 and 10 wt % of water in the feed and further swelling studies also supporting the pervaporation results.

(2015) Temperature-responsive poly(N-vinylcaprolactam-co-hydroxyethyl methacrylate) nanogels for controlled release studies of curcumin, Designed Monomers and Polymers, 18:8, 705-713, DOI: 10.1080/15685551.2015 A series of nanogels (NGs) were developed from N-vinylcaprolactam and hydroxyethyl methacrylate through free radical emulsion polymerization using methylene bis acrylamide as cross-linker. Curcumin, an anticancer agent was successfully loaded into these NGs via equilibrium in situ method. These NGs were characterized by Fourier transform spectroscopy (FTIR), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and dynamic light-scattering experimental (DLS) techniques. The formation of co-polymeric NGs was confirmed by FTIR analysis. DSC results reveal that the drug was molecularly dispersed in the NG networks. TEM results indicate the formation of NGs, in a spherical shape, with the size of 150 nm. The DLS results also support the formation and size of NGs. An in vitro release study indicates that the NGs may be potentially useful for targeted drug delivery applications.