Fabrication and Properties of Graphene Oxide/Sulfonated Polyethersulfone Layer-by-layer Assembled Polyester Fiber Composite Proton Exchange Membranes

Using the hydrogen-bonding interaction between graphene oxide（GO） and sulfonated polyethersulfone （SPES）, we constructed the multilayer structure of GO and SPES on the polyester tiber mats via layer-by-layer self-assembly. In each self-assembled layer, sulfonic acid groups are arranged along the a^s of fiber, which provides the long-range proton transmission channels, promoting the rapidly proton conduction. The performances of the composite membranes based on SPES and multilayer assembled polyester fiber mats were studied. The results show that the proton conductivity of composite membranes increases with the increasing assembly layers. At the same time, the mechanical properties and methanol-resistance of the composite membranes were obviously improved.

Strengthened graphene oxide/diazoresin multilayer composites from layer-by-layer assembly and cross-linking

The layer-by-layer assembly of graphene oxide and diazoresin is carried out via the electrostatic and hydrogen bond interactions on planar substrates and colloidal templates.The successful planar and spherical growth of multilayer could be investigated by UV-vis spectrophotometry and scanning electron microscopy,respectively.Subsequent UV irradiation or heating would convert the ionic bonds and hydrogen bonds to covalent bands,which significantly improves the stability of the multilayer composite against solvent etching.For the cross-linked core-shell composites,the template cores could be removed by dissolution and hollow microspheres are obtained.

界面自组装法制备高性能氧化石墨烯膜

为制备可靠、精确的分子筛氧化石墨烯(GO)膜,克服基于厚度调控的抽滤自组装GO膜分离性能提升和通量减小之间的矛盾关系,采用界面自组装法,制备了具有更加紧密层间结构的GO膜,并对其性能进行了表征。实验结果表明:与抽滤自组装法制备GO膜相比,界面自组装法可以实现更加紧密的层间结构;在化学环境相似的条件下,界面自组装膜的层间距可达0.75 nm,较抽滤自组装膜减小了0.10 nm左右;成膜机理和速率是GO膜层间结构的主要影响因素。将该膜用于金属离子水溶液的截留实验,结果表明:界面自组装GO膜对Mg^(2+)的截留率可达70%左右,是抽滤自组装膜的1.3倍。

氧化石墨烯的制备及其负载纳滤膜性能

纳滤膜在污水处理和海水淡化等方面具有独特的优势,因而一直是膜研究领域的热点。氧化石墨烯(GO)因自身特殊的分子层结构及表面电荷性质,可应用于复合纳滤膜的制备中。采用改进Hummers法制备得到氧化程度较高的GO,再通过压力辅助自组装法制得氧化石墨烯-聚偏氟乙烯(GO-PVDF)复合纳滤膜。通过对NaCl和Na_2SO_4进行脱除测试,研究负载量、盐溶液质量浓度等因素对GO-PVDF复合纳滤膜截留率和渗透通量的影响。实验结果表明,增大GO负载量有助于获得较好的脱盐效果。在相同条件下,GO-PVDF复合纳滤膜对Na_2SO_4的截留率高于对NaCl的截留率,且对低浓度盐溶液的脱除率更高。纳滤膜长周期稳定性测试表明,GO-PVDF复合纳滤膜的渗透通量和截留率基本保持稳定,经过12h后其对NaCl和Na_2SO_4的截留率分别可达58.9%和76.6%。

氧化石墨烯/聚丙烯腈小分子层层自组装复合膜的制备及研究

小分子层层自组装法制备得到复合膜。通过二乙烯三胺改性聚丙烯腈膜来增强复合层的稳定性,在小分子层层自组装过程中引入氧化石墨烯(GO)来提高分离膜的综合性能。采用扫描电子显微镜(SEM)、水接触角测试(WCA)、分离性能和抗污性能测试等手段对分离膜的表面形貌和性能进行了表征。研究表明添加GO能够有效提高分离膜的亲水性、渗透性、截留率和抗污性能。