采用离子交换法将十六烷基三苯基插入到钠基蒙脱土的层间得到4种不同季鏻阳离子含量的改性蒙脱土,通过热重分析(TGA)、X射线衍射法(XRD)和扫描电镜(SEM)表征了结构,并测试了其Zeta电位和抗菌活性.发现4种改性蒙脱土中季鏻阳离子的热分解起始温度都高于230℃,具有较好的热稳定性.并且随着改性蒙脱土中季鏻阳离子含量的增加,其层间距变大、Zeta电位升高、抗菌活性增强.钠基蒙脱土为片状结构,粒子之间相互缠绕在一起,而改性蒙脱土显示不规则形状.对季鏻阳离子含量为23.55wt%的QPC/MMT-3样品,其对大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)的最低抑菌浓度(MICs)分别为1.2和0.1g/L;与细菌接触24h后,1.0g/L的样品可杀死99.9%以上的E.coli,0.1g/L的样品可杀死所有的S.aureus.QPC/MMT-3还具有较好的耐水性能.
Four kinds of modified montmorillonites were prepared by introducing different content of hexadecyhriphenyl phosphonium cations into sodium montmorillonite (Na/MMT) through an ion-exchange method, and characterized using thermogravimetry (TGA), X-ray diffraction (XRD) and scanning electron microscope (SEM). Also the Zeta potentials and antibacterial activity of the modified montmorillonites were investigated. The onset temperatures of the decomposition for quaternary phosphonium cations in modified montmorillonites are all higher than 230℃, which have good thermal stability. For the montmorillonites, the interlayer spacings enlarge, the Zeta potentials increase and the antibacterial activity improves with the increase of the content of quaternary phosphonium cations. Na/MMT displays flake shape with the particles adhered and interwinded each other, while the modified montmorillonites are in irregular shape. QPC/MMT-3 containing 23. 55wt% quaternary phosphonium cations, possesses the minimal inhibitory concentration (MICs) against E. coli and S. aureus of 1.2g/L and 0. 1g/L, respectively. After contacting the bacteria for 24h, 1.0g/L of QPC/MMT-3 is able to kill more than 99.9% E. coli, and nearly all the E. coll. Moreover, QPC/MMT-3 has good water resistance.