School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei, 430070, China.
School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei, 430070, China; Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei, 430070, China.
Carbohydr Polym. 2018 Oct 15;198:518-528. doi: 10.1016/j.carbpol.2018.06.124. Epub 2018 Jun 30.
Poly(vinyl alcohol)-sodium alginate-chitosan-montmorillonite nanosheets (MMTNS) hydrogel beads with porous and steady structure were fabricated via hydrogen-bond and electrostatic interactions, and were characterized by FTIR, TG, SEM and effecting tests. The results suggested MMTNS could support and maintain the porous structure, making an open excess for MB molecules. The increasing proportion of MMTNS in hydrogel beads enhanced the MB removal. Hydrogel beads possessed higher affinity to MB at high pHs due to the stronger electronegativity triggered by deprotonation of hydroxyls. Moreover, hydrogel beads had a good stability and reusability. The adsorption process was correlated with Elovich kinetics model, and fitted well with Freundlich, Redlich-Peterson and Sips isotherm models. The adsorption of MB on hydrogel beads was a disorderliness, endothermic and spontaneous process detected by the thrmodynamic. MB molecules reacted with the oxygen atoms in hydroxyl and substitute the Na in MMTNS were proved by EDS, XPS and Na concentration variation.
通过氢键和静电相互作用制备了具有多孔稳定结构的聚乙烯醇-海藻酸钠-壳聚糖-蒙脱土纳米片（MMTNS）水凝胶珠，并通过 FTIR、TG、SEM 和效应测试进行了表征。结果表明，MMTNS 可以支撑和维持多孔结构，为 MB 分子提供开放的过剩空间。水凝胶珠中 MMTNS 的比例增加增强了对 MB 的去除。由于羟基去质子化引发的电负性增强，水凝胶珠在较高 pH 值下对 MB 具有更高的亲和力。此外，水凝胶珠具有良好的稳定性和可重复使用性。吸附过程与 Elovich 动力学模型相关，并且与 Freundlich、Redlich-Peterson 和 Sips 等温模型拟合良好。通过热力学检测到 MB 在水凝胶珠上的吸附是无序的、吸热的和自发的过程。MB 分子与羟基中的氧原子反应，并取代 MMTNS 中的 Na，这一点通过 EDS、XPS 和 Na 浓度变化得到了证明。
