对NaOH/尿素法制备纤维素膜的孔结构的控制

为达到采用环境友好的工艺制备孔结构可控的纤维素膜的目的,以wNaOH=6%和w尿素=4%的水溶液为纤维素溶剂,采用浸渍沉淀相分离法制备了纤维素膜,考察了纤维素浓度、凝固浴种类、不溶性致孔剂添加量对纤维素膜微观形貌、平均孔径和孔隙率的影响规律。结果表明:使用wHCl=3%的水溶液做凝固浴,通过向制膜液中添加微量ZnO粉体,可制得孔隙率0.90左右、平均孔径成倍可调的纤维素膜。使用醇类做凝固浴可显著降低纤维素膜的孔隙率。上述因子的组合为制备具有灵活的孔隙率和平均孔径的纤维素膜提供了可能。

Pore structure control of cellulose membrane prepared using the NaOH/urea method

Cellulose membranes with controllable pore structures were manufactured using an environmentally friendly process with an aqueous solution containing wNaOH=4% and wurea=6% as the solvent.The cellulose membranes were prepared using the immersion precipitation phase inversion technique.The prepared cellulose membrane was observed by SEM and characterized with the average pore size and porosity.Tests investigated the effect of the cellulose concentration,type of coagulant,and the addition of an insoluble template on the membrane.The results show that with trace amounts of ZnO powder,cellulose membranes was obtained with about 0.9 porosity and widely adjustable average pore size by coagulation in an aqueous solution containing wHCl=3%.The porosity of the cellulose membrane was significantly reduced by using ethanol as the coagulant.Control of these factors allows preparation of cellulose membranes with flexible porosities and average pore sizes.