Preparation of Cotton Gauze Coated with Carboxymethyl Chitosan and its Utilization for Water Filtration

摘要

Contaminated water represented the main source of communicable diseases; therefore the decontamination process of waste water is essential to remove these pathogenic bacteria. The filtration process is a more favorable process than other chemical methods due to the harmful hazards of chlorinated materials used. In the present work cotton gauze coated with carboxymethylchitosan is used as water filter for gram-positive and gram-negative bacteria disinfection. We choose cotton gauze as cellulosic substrate as it is cheap, easily available and has an open structure suitable for continuous filtration systems. Carboxymethyl chitosan (CMCS) as water soluble chitosan derivative has been prepared in accordance with the methodology in our previous study by the reaction of chitosan with monochloroacetic acid in the presence of sodium hydroxide for 3 hours at 60oC (20). The prepared CMCS was characterized by using nitrogen content and FT-IR spectra. The FT-IR spectra demonstrated the conversion of chitosan to carboxymethyl chitosan. Carboxymethylchitosan treated Cotton gauze has been prepared via pad-dry-cure method, to be used for water filtration against gram-positive and gram-negative bacteria. The cotton gauze was characterized before and after treatment with CMCCS using various tools such as nitrogen content, FT-IR spectra, scan electron microscope (SEM) and thermal gravimetric analysis (TGA). FT-IR spectra confirm the presence of CMCS on cotton gauze. Antibacterial activity of this cotton gauze has been evaluated by using a bacterial count method. The results show that water filters cause a reduction of bacterial count. This reduction of bacteria depends on the amount of chitosan on the fiber. Based on our results, this composite had great promising to be used as bacterial filter.