Synthesis of morphology-controlled silver nanostructures by electrodeposition

Nanostructured silver was obtained by potentiostatic electrolysis.The effects of ionized surfactant(sodium dodecanesulphonate)and the substrate(Cu and Ti)on the morphology of depositions were investigated.It is found that morphologies of silver nanostructures can be simply controlled via change of the substrate.Spherical Ag nanoparticles with narrow size distribution were obtained by electrodeposition in Ag NO3-SDS aqueous solution on copper substrate.In the case of titanium substrate,silver dendrite structures were obtained.Despite of different morphologies,XRD and TEM results showed that the as-prepared samples belong to face-centered cubic silver structure with good crystallinity.The formation mechanism of different silver nanostructures was discussed.

Preparation of Gold Nanoparticles Loaded Chitin Nanofiber Composite

Chitin nanofibers (CNFs) processed from second most abundant biomolecule chitin were loaded with gold metallic nanoparticles (Au NPs) to obtained hybrid organic-inorganic composite which was molded in different forms dispersion, flakes, powder, and transparent thin film. First pre-organized Au NPs were prepared in soluble triblock copolymer poly (methyl vinyl ether) (PMVE) by reduction of gold precursor salt (HAuCl43H2O) by NaBH4 then NPs were mixed with diluted CNFs suspension to obtain CNFs-Au NPs composite. CNFs of width 25 - 40 nm were prepared by combination of chemical and mechanical processing in wet acidic condition from 1 wt% crab shell chitin slurry. When polymer stabilized Au NPs blended with CNF suspension, all Au NPs and 56% polymer were found mass transferred from water phase to entangle with more polar moieties of chitin. Composite’s suspension and compressed dried film were characterized by recording digital images, UV-vis, TEM, SEM, and XRD spectroscopies. When 70 m thin non transparent composite film was impregnated with tricyclodecane dimethanol dimethacrylate (TCDDMA) resin and subsequent polymerized with photoinitiator 2-hydroxy-2-methylpropiophenone, the film became transparent due to filling of nanosized CNFs in the cages of the resin.