School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei, 430070, People's Republic of China.
Nanotechnology. 2018 Jan 12;29(2):025605. doi: 10.1088/1361-6528/aa9ba4.
Novel montmorillonite-nanosheet/chitosan (MMTNS/CS) hydrogels fabricated via the self-assembly of exfoliated MMTNS and CS chains were investigated. The exfoliation of MMTNS, self-assembly mechanism and structure of MMTNS/CS hydrogels were characterized by an atomic force microscope, scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscope, energy-dispersive x-ray spectroscope and Brunauer-Emmett-Teller analyzer, respectively. The results indicated that MMT could be easily exfoliated to nanosheets with a thickness of 1 ∼ 5 nm in aqueous solution by an ultrasonic base upon interlayer hydration. The formation mechanism of the self-assembly hydrogels was due to the hydrogen bond (-OH ··· NH-) and electrostatic interaction between the MMTNS and CS. The MMTNSs were connected consecutively by CS in-plane to form a huge slice. The porous structure of the hydrogels was controllable by adjusting the MMTNS/CS mass ratio. The hydrogels could be used as adsorbents for sewage treatments, carriers for drugs, microorganisms and catalyzers due to their controllable porous structure and tremendous specific surface area which were derived from the completely exfoliated MMTNS.
通过剥离的蒙脱土纳米片和 CS 链的自组装制备了新型蒙脱土纳米片/壳聚糖（MMTNS/CS）水凝胶。通过原子力显微镜、扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱仪、能谱仪和 Brunauer-Emmett-Teller 分析仪分别对 MMTNS 的剥离、自组装机制和 MMTNS/CS 水凝胶的结构进行了表征。结果表明，MMT 可以在水溶液中通过超声基轻易地剥离成厚度为 1~5nm 的纳米片，这是由于层间水合作用。自组装水凝胶的形成机制是由于 MMTNS 和 CS 之间的氢键（-OH···NH-）和静电相互作用。MMTNS 被 CS 在平面内连续连接形成巨大的薄片。通过调整 MMTNS/CS 的质量比，可以控制水凝胶的多孔结构。由于完全剥离的 MMTNS 具有可控的多孔结构和巨大的比表面积，水凝胶可用作污水处理的吸附剂、药物、微生物和催化剂的载体。
