MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University , Hangzhou 310027, China.
Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province , Hangzhou 310027, China.
ACS Appl Mater Interfaces. 2017 Jan 25;9(3):2966-2972. doi: 10.1021/acsami.6b13761. Epub 2017 Jan 9.
A defect-free and stable selective layer is of critical significance for thin film composite membrane with excellent separation performance and service durability. We report a facial strategy for fabricating thin film nanocomposite (TFN) nanofltration membranes (NFMs) based on the codeposition of polydopamine, polyetheylenimine, and silica nanoparticles. Tripled water flux can be obtained from the TFN NFMs as compared with those NFMs without silica nanoparticles. This is ascribed to the improved wettability of the membrane surfaces and the enlarged pore sizes of the selective layer. The interfacial compatibility of the inorganic fillers and the polymer matrices can be enhanced by the electrostatic interactions of silica nanoparticles with polyethylenimine and the adhesive characteristics of polydopamine, resulting in a defect-free selective layer and then good rejection for both bivalent cations and neutral solutes. The rigid silica nanoparticles also improve the surface mechanical strength of the TFN NFMs effectively and lead to structural stability and compaction resistance during the long-term filtration process.
无缺陷且稳定的选择层对于具有优异分离性能和耐用性的薄膜复合膜至关重要。我们报告了一种在聚多巴胺、聚乙烯亚胺和硅纳米粒子共沉积的基础上制备薄膜纳米复合（TFN）纳滤膜（NFM）的简便策略。与不含硅纳米粒子的 NFM 相比，TFN NFM 的水通量提高了两倍。这归因于膜表面润湿性的提高和选择性层孔径的增大。硅纳米粒子与聚乙烯亚胺的静电相互作用以及聚多巴胺的黏附特性增强了无机填料与聚合物基质之间的界面相容性，从而形成无缺陷的选择性层，对二价阳离子和中性溶质具有良好的截留率。刚性的硅纳米粒子还能有效地提高 TFN NFM 的表面机械强度，在长期过滤过程中导致结构稳定性和抗压能力。
