氧化石墨烯/聚电解质层层自组装制备单价离子选择性膜

采用层层自组装法在改性聚丙烯腈(PAN)膜表面交替沉积聚乙烯亚胺(PEI)和聚丙烯酸-氧化石墨烯(PAA-GO)混合液,制得了单价离子选择性复合膜。X射线衍射(XRD)测试结果表明成功合成了氧化石墨烯(GO)并在复合膜中均匀分散。扫描电镜(SEM)观察结果证实了多层聚电解质PEI/PAA-GO成功地组装在基膜上,并用紫外-可见(UV-Vis)光谱进一步证实了组装过程的均匀性和连续性。接触角和性能测试表明加入GO后,复合膜的亲水性和单价阳离子的选择性明显增大。这种高通量、高选择性的防污复合膜在分离和水的软化方面有很好的应用前景。

Layer-by-Layer Assembly of Graphene Oxide and Polyelectrolyte Composite Membranes for Monovalent Cation Separation

Graphene oxide (GO) composite membranes were fabricated via layer-by-layer (LBL) assembling poly(ethylenimine) (PEI) and a mixture of GO and poly(acrylic acid) (PAA) on a poly(acrylonitrile) (PAN) support membrane. The composite membranes and their application performance were characterized and evaluated. The X-ray powder diffraction (XRD) spectrum shows that GO was successfully synthesized by the modified Hummers method, and it was homogenously dispersed in the composite membranes. Scanning electron microscopy (SEM) shows the successful assembly of multiple polyelectrolyte PEI and a mixture of GO and PAA bilayers on the PAN support membrane. The ultraviolet-visible (UV-Vis) spectrum indicates that the uniformity and continuity of the composite membrane were enhanced with the increasing number of assembled layers. The hydrophilic and selectivity tests reveals that the addition of GO decreased the water contact angle and enhanced the selectivity for monovalent cations of the multilayer polyelectrolyte composite membranes. All these advantages combine to fabricate a high-flux, high selectivity, and anti-fouling composite membrane for separation applications and water softening.