Ag/低分子量壳聚糖复合胶乳的制备及抗菌性能

采用原位法和液相化学还原法制备了Ag/低分子量壳聚糖(LMWC)和Ag/LMWC-聚吡咯(PPy)复合胶乳,分析了各种工艺条件对复合胶乳中纳米Ag粒子粒径及粒度分布的影响规律,并确定了复合胶乳较适宜的合成条件。采用UV-Vis、TEM、FTIR及 XRD对复合胶乳的组成和纳米Ag的形态进行了表征。结果显示: Ag/LMWC 和 Ag/LMWC-PPy复合胶乳中的纳米Ag晶体为面心立方结构,平均粒径约为10~20 nm。抗菌测试结果表明: LMWC(黏均分子量M_η=4.3×10⁵)的抗菌效果优于未降解的原始壳聚糖(CS),由于纳米Ag的引入,Ag/LMWC和Ag/LMWC-PPy复合胶乳对大肠杆菌和金黄色葡萄球菌与单一的LMWC相比均具有较高的抑菌活性。

Preparation of Ag/low molecular weight chitosan composite colloids and their antibacterial activities

Silver/low molecular weight chitosan(Ag/LMWC) and Ag/LMWC-polypyrrole (PPy) composite colloids were prepared in situ by liquid chemical reduction method.The effects of various process conditions on the size and size distribution of Ag nanoparticles in composite colloids were investigated.And the appropriate synthetic conditions were determined.The component of the composite colloids and the morphological structure of Ag nanoparticles were characterized by UV-Vis, TEM, FTIR and XRD.The results show that the structure of Ag nanoparticles in the composite colloids is face-centered cubic with average particle size about 10-20 nm.The antibacterial tests reveal that the inhibitory of LMWC (viscosity-average molecular weight M_η=4.3×10⁵) is stronger than that of the original chitosan (CS).Moreover, compared with the single LMWC, the antibacterial activities of Ag/LMWC and Ag/LMWC-PPy composite colloids to Escherichia coli and Staphylococcus aureus are very excellent due to the introduction of Ag nanoparticles.