超亲水木质素磺酸盐/超支化聚酰胺杂化接枝聚偏氟乙烯微滤膜的制备及分离性能研究

Preparation and Separation Properties of Superhydrophilic Lignin Sulfonate/Hyperbranched Polyamide Hybrid Grafted Poly(vinylidene fluoride)Microfiltration Membranes

以聚偏氟乙烯(PVDF)微孔膜为基底,经碱化、表面接枝聚合甲基丙烯酸缩水甘油酯,再与胺化木质素磺酸钠(LA)、超支化聚酰胺(HP)和聚乙二醇二缩水甘油醚(PEGDGE)混合交联反应,制备了木质素磺酸钠/超支化聚酰胺杂化凝胶改性的超亲水PVDF-HPAS膜。所制PVDF-HPAS膜呈超亲水性,纯水通量为8596 L·m^(–2)·h^(–1)。对刚果红(CR)、直接红80、达旦黄等阴离子染料溶液表现出优异的分离性能,分离效率均可达100%,且对CR的分离通量可达3942 L·m^(–2)·h^(–1)。同时,PVDF-HPAS膜具有优异的油水乳液分离性能,正己烷乳液的分离通量为3152 L·m^(–2)·h^(–1),分离效率大于98%。此外,PVDF-HPAS展现了良好的通量回复性和抗污染性。该改性膜优异性能归于三维网络结构超亲水凝胶层的静电作用对染料截留和吸附,大量氨基、羟基等基团的破乳作用,及三维结构协同PVDF膜多孔结构提高的水传质作用。

To quickly and efficiently remove the organic dye and oil pollutants in the wastewater,poly-(vinylidene fluoride)(PVDF)microporous membrane as the substrate was first treated with alkalization and surface grafting polymerization of glycidyl methacrylate,and then crosslinked with sodium amine lignosulfonate(LA)and hyperbranched polyamide(HP).Finally the superhydrophilic lignin sulfonate/hyperbranched polyamide hybrid hydrogel modified PVDF membrane(PVDF-HPAS)was prepared.The PVDF-HPAS membrane showed excellent separation performance for the anion dye solutions,the separation fluxes for CR was 3942 L·m^(–2)·h^(–1),and the separation efficiency can reach 100%.PVDF-HPAS has excellent oil/water emulsion separation flux and efficiency.The flux and separation efficiency of n-hexane emulsion were 3152 L·m^(–2)·h^(–1)and more than 98%,respectively.In addition,PVDF-HPAS membrane has good reusability and antifouling properties.The excellent performance of the modified film is attributed to the electrostatic effect of the three-dimensional network structure superhydrophilic gel layer on the dye retention and adsorption,the demulsification of a large number of amino and hydroxyl groups,and the water mass transfer effect of the three-dimensional structure and the porous structure of the PVDF membrane.