绿色合成载银壳聚糖及其等温线、动力学及抑菌性

以吸附绿色合成法制备载银壳聚糖,采用X射线衍射(XRD)、场发射扫描电镜(FESEM)和热重分析研究其微观结构和热稳定性,并研究了壳聚糖对银离子的吸附模型,以此为抗菌材料,通过平板扩散板法评价载银壳聚糖的抗菌效果。实验结果表明:银离子在多糖结构中的引入影响了其原有的晶体结构,提升了其热稳定性。壳聚糖对银离子的吸附等温线与Langmuir和Dubinin-Radushkevich方程相一致,说明了壳聚糖中银离子的吸附过程符合单层吸附和化学吸附,并且根据Langmiur方程计算壳聚糖对银离子的最大吸附量为478.09 mg/g,含银量为32.34%,与Dubinin-Radushkevich计算结果一致。银含量饱和的载银壳聚糖对大肠杆菌(Escherichia coli)和金黄色葡萄球菌(Staphylococcus aureus)具有良好的抗菌性能,其最小抑菌浓度为80 μg/mL。

Synthesis of Ag-Chitosan by Green Route and Its Isotherms,Kinetic and Antimicrobial Activity

A green route, namely adsorption methods, has been developed to synthesize silver-loaded chitosan(Ag-chitosan). The microstructure and thermal stability were studied by X-ray diffraction (XRD), field emission scanning electric mirror (FESEM) and thermal weight analysis. The adsorption model of chitosan on silver was also studied. The antibacterial effect of Ag-chitosan was evaluated by plate diffusion board method. The results show that the introduction of silver ions in the polysaccharide structure affects its original crystal structure and improves its thermal stability. The adsorption isotherm of chitosan to silver ions is consistent with the Langmuir and Dubinin-Radushkevich equations, indicating that the adsorption process of silver ions in chitosan complies with single layer adsorption and chemical adsorption, and the maximum adsorption of chitosan to silver ions is 478.09 mg/g, silver content is 32.34%, which is consistent with the Dubinin-Radushkevich calculation. Therefore, chitosan with 32.34% silver content was obtained and tested against Escherichia coli and Staphylococcus aureus, which is considered one of the most widespread wound burn infectious bacteria. The antibacterial test results indicate that Ag-chitosan has favourable antibacterial property and MIC≤80 μg/mL against Escherichia coli and Staphylococcus aureus.