Fabrication of Chitosan/Silver Hydrogel Membrane and Effect of Membrane Preparation Method on Antibacterial Property

Abstract

For membrane pretreatment of seawater reverse osmosis desalination, the degradation of the membrane performance by biofouling is a serious problem. Chitosan hydrogel membranes including silver, which are inorganic antibacterial reagents, were fabricated for the antibacterial activity enhancement of a separation membrane. They were prepared using two methods: the immersion method and the mixture method. We investigated the effects of a membrane preparation method on membrane properties, water permeability and antibacterial activity. We analyzed the obtained membrane with Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), thermogravimetry-differential thermal analysis (TG-DTA). It was found that the hydrogel membrane prepared by the mixture method contained silver particles. On the other hand, the hydrogel membrane prepared using the immersion method contained silver in ion form. The water content of the membrane decreased with increase of the silver content, and the water flux increased with increase of the water content. In addition, we evaluated antibacterial activity of the hydrogel membrane by the conductance method. The chitosan/silver hydrogel membranes showed a distinctive inhibitory effect for growth of Escherichia coli and Staphylococcus aureus. The chitosan/silver hydrogel membranes prepared using to immersion method showed strong antibacterial activity compared with that prepared by the mixture method.