Assembly and antibacterial properties of chitosan derivatives organic montmorillonite nanocomposites doped with silver

Chitosan derivatives organic montmorillonite first prepared by stepwise assembly method, then which be used to prepare quaternised carboxymethyl chitosan of organic modified montmorillonite silver (QCOM-Ag) by complex impregnation; finally using X-ray diffraction analysis, SEM to characterise the structure and morphology of samples; antimicrobial properties of multiple samples tested by filter paper method and multiple dilution method. The results showed the synthesis of silver carboxymethyl chitosan quaternary complex solution intercalation by its intercalation into cetyltrimethyl ammonium bromide organic modified montmorillonite layer, and the layer spacing of up to 0998 nm. With the mass ratios of quaternised carboxymethyl chitosan to organic montmorillonite increased from 1:1 to 8:1 in QCOM nanocomposites, the results also showed that the characterisation of chitosan after the silver surface is rough, there is little particulate matter evenly dispersed in the surface thereof. SEM micrographs showed that Ag NP was mainly spherical, and few had square or bar form. Compared with carboxymethyl groups, quaternary ammonium groups are more beneficial to prepare Ag NP, and silver has been loaded onto QCOM. Inhibition experiments showed that this bacteriostatic ring-controlled, sustained intermediate Gram-positive bacteria S. aureus has a good antibacterial effect; minimal inhibitory concentration of QCOM-11-Ag antibacterial liquid for B. subtilis obtained by multiple experiments was 200 ?g mL-1. The antibacterial effect of QCOM-11-Ag on B. subtilis is more obvious, yet minimal inhibitory concentrations of S. aureus and E. coli are 500 and 250 ?g mL-1, respectively. © W. S. Maney & Son Ltd 2015.