Organosilane-functionalized graphene oxide for enhanced antifouling and mechanical properties of polyvinylidene fluoride ultrafiltration membranes

• Published in: Journal of membrane science Vol. 458; pp. 1 - 13
• Main Authors: Xu, Zhiwei, Zhang, Jiguo, Shan, Mingjing, Li, Yinglin, Li, Baodong, Niu, Jiarong, Zhou, Baoming, Qian, Xiaoming
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2014; Elsevier
• Subjects: Antifouling; Antifouling performance; Applied sciences; Chemistry; Colloidal state and disperse state; Covalence; Exact sciences and technology; Exchange resins and membranes; Flux; Forms of application and semi-finished materials; Fouling; General and physical chemistry; Graphene; Graphene oxide; Graphene oxide functionalization; Hybrid membranes; Mechanical performance; Membranes; Oxides; Polymer industry, paints, wood; Polyvinylidene fluorides; Technology of polymers; Hybrid membranes; Antifouling performance; Graphene oxide; Mechanical performance; Graphene oxide functionalization; Membrane separation; Polymeric membrane; Ultrafiltration; Functionalization; Vinylidene fluoride polymer; Mechanical properties
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2014.01.050

Functionalized graphene oxide (f-GO) was synthesized by a simple covalent functionalization with 3-aminopropyltriethoxysilane (APTS). The hybrid polyvinylidene fluoride (PVDF) ultrafiltration membranes were then prepared by adding different ratios of graphene oxide (GO) and f-GO via phase inversion induced by immersion precipitation technique. Zeta potential demonstrated that covalent functionalization of GO with APTS was favorable for their homogeneous dispersion in organic solvents. SEM images showed that very large channel appeared in top-layer by the addition of additives. Furthermore, the PVDF/f-GO membranes exhibited superior hydrophilicity, water flux, BSA flux and rejection rate than nascent PVDF membranes and PVDF/GO membranes. Filtration results indicated that the fouling resistance parameters were significantly declined due to higher hydrophilicity of hybrid membranes. An atomic force microscope (AFM) analysis with a BSA-immobilized tip revealed that the adhesion forces between membrane and foulants increased in the following order: PVDF/f-GO<PVDF/GO<PVDF. After a ternary cycle BSA solution inner fouling process, PVDF/f-GO membranes exhibited higher water flux recovery ratio (FRR) value than that of PVDF/GO. Meanwhile, tensile strength and elongation-at-break of PVDF/f-GO membranes were increased by 69.01% and 48.38% compared with those of PVDF/GO membranes, which is believed to be attributed to the strong interfacial interaction between f-GO and matrix by covalent functionalization of GO. As a result, GO functionalization will provide a promising method to fabricate graphene-based hybrid membranes with effective reinforced permeation, antifouling and mechanical performance. Due to reduced agglomeration of graphene oxide and enhanced interaction between additives and polymer matrix, the performances of organosilane-functionalized graphene oxide-based ultrafiltration membranes outweigh others. [Display omitted] •Effect of organosilane-functionalized graphene oxide was remarkable.•Foulants tended to be deposited on the rough surface.•Permeability and antifouling performance were increased significantly.•Tensile strength was improved obviously.