Preparation of Cellulose Hollow Fiber Membrane from Bamboo Pulp/1-Butyl-3-Methylimidazolium Chloride/Dimethylsulfoxide System

In this paper, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was synthesized and used as solvent to dissolve bamboo pulp. Dimethylsulfoxide (DMSO) was selected as cosolvent to adjust the solution viscosity. As compared with the bamboo pulp/[Bmim]Cl system, the addition of DMSO decreases the solution viscosity dramatically. Afterward, cellulose hollow fiber membranes were prepared by dry-wet spinning process using 75 wt % [Bmim]Cl + 25 wt % DMSO as solvent. Scanning electron microscope (SEM), mechanical testing, pure water permeability, and retention rate were used to characterize its properties, respectively. The SEM result shows that the prepared cellulose hollow fiber membrane presents dense surface structure, which leads to a relative high tensile strength and retention rate to bovine serum albumin, i.e. 28 MPa and 98%, respectively, but a relative low pure water permeability, i.e. 83 L/m2·h. In the end, the [Bmim]Cl is recovered by azeotropy, and the recycling yield reaches 99 wt %.