Sadiya Anjum; Shamayita Patra; Bhuvanesh Gupta
Abstract
Functional patterning and alignment of metallic nanoparticles are gaining enormous interest in electronics, photonics and sensing areas. In the present work, we have investigated the water-in-oil emulsion polymerization for the growth of functional silver nanoparticles within polyacrylamide chains. These ...
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Functional patterning and alignment of metallic nanoparticles are gaining enormous interest in electronics, photonics and sensing areas. In the present work, we have investigated the water-in-oil emulsion polymerization for the growth of functional silver nanoparticles within polyacrylamide chains. These functional nanoparticles undergo different alignment and patterning with the variation of surfactant concentration. As the surfactant in the emulsion increases, the resultant nanoparticles are linearly aligned into nanofiber with some branching. However, at 10% concentration of surfactant, these fibers are fused and quasi-circular pattern was observed. The average size of the nanoparticles was observed to be in the range of 5 to 25 nm. Whereas, the size of line pattern was observed in some microns with branching or interconnectivity of nanometer range.
Sadiya Anjum; Shamayita Patra; Bhuvanesh Gupta
Abstract
This study is aimed at the development of nanosilver embedded polyacrylamide (PAAm) bioactive nanogels and antimicrobial behavior of these functional nanogels. Nanogels were synthesized by polymerization of the monomer/silver nitrate as water phase in nanoemulsion using gamma irradiation process where ...
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This study is aimed at the development of nanosilver embedded polyacrylamide (PAAm) bioactive nanogels and antimicrobial behavior of these functional nanogels. Nanogels were synthesized by polymerization of the monomer/silver nitrate as water phase in nanoemulsion using gamma irradiation process where radiation helps in the polymerization, nanogel crosslinking and the reduction of silver nitrate to nanosilver. Homogeneously dispersed nanosilver particles embedded within PAAm nanogel matrix having size in the range of 10-50 nm were achieved depending on the reaction conditions. Minimum inhibitory concentration and bacteriostatic efficacy of nanogels were investigated against bacterial strains of Escherichia coli and Staphylococcus aureus. The bioactive nanogels showed very effective antimicrobial behavior and showed mortality against both bacterial strains at very low concentration. The bactericidal action of functional silver nanoparticles against Escherichia coli was investigated by TEM analysis. It was observed that after treatment with bioactive nanogel, the cell wall of Escherichia coli was completely destroyed and punctured. Here, we propose that the bioactive nanogel by virtue of its hydrophilic and polar functionality is very much suitable for linking to different biomaterials for developing antimicrobial surfaces especially in surgical devices and synthetic implants.
Vandana Singh; Stuti Tiwari; Sadanand Pandey; Rashmi Sanghi
Abstract
This study puts forward the synthesis of an excellent cadmium adsorbent having unprecedented high capacity (Qmax = 5000 mg g -1 ) to capture cadmium ions from synthetic cadmium solution. To synthesize the adsorbent (A700), base catalyzed polymerization of tetra ethylorthosilicate (TEOS) was conducted ...
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This study puts forward the synthesis of an excellent cadmium adsorbent having unprecedented high capacity (Qmax = 5000 mg g -1 ) to capture cadmium ions from synthetic cadmium solution. To synthesize the adsorbent (A700), base catalyzed polymerization of tetra ethylorthosilicate (TEOS) was conducted under the sacrificial templation effect of poly(acrylamide) grafted Cassia grandis seed gum (CG) while using H2O, TEOS and EtOH in 8:1:1: ratio (v/v). The CG inspired adsorbent was characterized by FTIR, XRD and SEM, both before and after cadmium adsorption. The adsorption parameters for the synthesized adsorbent were optimized by performing the batch adsorption studies under different pH, initial cadmium concentration, adsorbent dose, and contact time. The adsorption showed pseudo second order kinetics with a rate constant of 1.55 x 10 -4 g mg -1 min -1 at 450 mg mL -1 Cd(II) concentration. The thermodynamic study showed that the adsorption is endothermic and spontaneous. The adsorbent could be successfully reused for three cycles. The present adsorbent is not only very efficient in cadmium uptake; it is greener than the contemporary porous silica adsorbents derived through templation of pure synthetic polymers or surfactants. Moreover the source polysaccharide used for its synthesis is abundant and cheap. This hybrid can utilized as versatile and sustainable adsorbent for cadmium recovery from industrial wastes.
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