Preparation Of Ag-polyvinyl Alcohol Nanofibers And Their Antibacterial Property

Electrospinning is currently one of the most versatile and promising processes for producing continuous nanofibers due to its capability and feasibility in generating large quantities of nanofibers at relatively low cost. Polymer/metal composite nanofibers prepared via electrospinning combine the advantages of composite materials and nanofibers, widen the applications of composite materials.PVA nanofibers were fabricated by electrospinning method. The effect of parameters such as concentration of PVA, voltage, inject-speed, C-SD, and the environment on the micrograph of composite fibers was studied. The results educed the optimal technological conditions of PVA nanofibers preparation, i.e., PVA concentration was 8%, the voltage was 16kV, inject-speed was 0.025ml/min and C-SD was 15cm.The silver nanoparticles in the nanofibers membranes were formed by thermal treatment and UV- irradiation treatment. The X-ray diffraction (XRD) results showed that the Ag+ in the nano-fibers membranes was reduced to Ag0, and the crystal plane of Ag0 implied the persistence of FCC silver phase, moreover, the XRD pattern proved that the after treatment improved the degree of crystallinity of PVA. The incorporation of sliver acetate/silver and PVA was investigated by FT-IR spectroscopy, and the results indicated that there was complexation between silver acetate and PVA, but there was no chemical bonding between silver and PVA. Differential scanning calorimentry (DSC) revealed the presence of silver can improve Tg of PVA.There were two methods we used to check the antimicrobial ability of Ag/PVA nano-fibers membranes, ZI (Zones of inhibition) and TA (Turbid meter Analysis), while staphylococcus and Escherichia were applied to test the membranes, on the behalf of the common bacterium. The ZI results showed that the membranes had effective antimicrobial ability; the thermal treated membranes were more effective than UV-treated ones. Besides the content of the silver, the size of silver nano-particles and the fiber diameter can also affect the antimicrobial ability. ZI and TA results were also suggested that Escherichia was killed easily by thermal treated membranes, compared to Escherichia.