Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos SP, Caixa Postal 780, 13560-970, Brazil.
Carbohydr Polym. 2017 Sep 1;171:202-210. doi: 10.1016/j.carbpol.2017.05.021. Epub 2017 May 5.
Silver nanoparticles (AgNPs) were synthetized on chitosans/montmorillonite nanocomposite films by photochemical method. Nanocomposites were prepared using chitosans with different molar masses and deacetylation degrees, as well as modified with diethylaminoethyl (DEAE) and dodecyl groups. AgNPs formation on the films was followed by the appearance of the plasmon band around 440nm as a function of irradiation time. TEM images revealed AgNPs with spherical morphology for all nanocomposites. For nanocomposites using modified chitosans, the AgNPs synthesis occurred quickly (1.5h) while for the others films it was above 11h. The film of modified chitosan with dodecyl and DEAE groups presented smaller and more uniform nanoparticles size along mixture of exfoliated and intercalated structures. This modified chitosan is an amphiphilic compound that can act controlling the size/shape of the AgNPs. The results of antibacterial activity suggested that all nanocomposite-AgNPs films inhibited the growth of Escherichia coli and Bacillus subtilis.
银纳米粒子（AgNPs）通过光化学法在壳聚糖/蒙脱石纳米复合材料薄膜上合成。纳米复合材料是用具有不同摩尔质量和脱乙酰度的壳聚糖制备的，并用二乙氨基乙基（DEAE）和十二烷基基团进行了修饰。随着辐照时间的增加，薄膜上出现了约 440nm 的等离子体带，表明 AgNPs 的形成。TEM 图像显示所有纳米复合材料均具有球形形态的 AgNPs。对于使用改性壳聚糖的纳米复合材料，AgNPs 的合成很快（1.5h），而对于其他薄膜则超过 11h。带有十二烷基和 DEAE 基团的改性壳聚糖的薄膜具有更小且更均匀的纳米颗粒尺寸，同时存在剥离和插层结构的混合物。这种改性壳聚糖是一种两亲性化合物，可以控制 AgNPs 的尺寸/形状。抗菌活性的结果表明，所有纳米复合材料-AgNPs 薄膜均抑制了大肠杆菌和枯草芽孢杆菌的生长。
