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壳聚糖经羧甲基化改性后得到水溶性较高的羧甲基壳聚糖(OCMC),它具有优良的稳定性和抗菌性。对比OCMC在不同溶剂中的溶解度,发现OCMC在2wt%乙酸溶液中的溶解性最好。将OCMC与纳米Ag(AgNPs)复合得到Ag-OCMC复合微粒,采用UV-Vis、FTIR、XPS、TEM、SEM和TG-DTA对Ag-OCMC复合微粒的组成、微观结构和热性能进行表征。以大肠杆菌和金黄色葡萄球菌为模型菌种测试Ag-OCMC复合微粒对革兰氏菌的抗菌性能。结果表明:AgNPs为面心立方晶型,平均粒径为40~50nm;AgNPs的引入提高了壳聚糖和OCMC的分解温度。Ag-OCMC复合微粒对革兰氏菌的抑菌活性明显高于单一壳聚糖基抗菌剂。
Chitosan modified by carboxymethylation to obtain higher water-soluble carboxymethyl chitosan (OCMC), which has excellent stability and antibacterial properties. In contrast to the solubility of OCMC in different solvents, OCMC was found to have the best solubility in a 2 wt% acetic acid solution. The composition, microstructure and thermal properties of Ag-OCMC composite particles were characterized by UV-Vis, FTIR, XPS, TEM, TG-DTA and Ag-OCMC composite particles. The antibacterial activity of Ag-OCMC composite particles against Gram-positive bacteria was tested by using Escherichia coli and Staphylococcus aureus as model strains. The results show that the AgNPs are face-centered cubic crystals and the average particle size is 40-50 nm. The introduction of AgNPs increases the decomposition temperature of chitosan and OCMC. Ag-OCMC composite antibacterial activity of Gram-positive bacteria was significantly higher than a single chitosan antibacterial agent.