静电纺丝纤维膜水力渗透性研究

Hydraulic permeability of electrospun fibrous membranes

通过静电纺丝技术纺制不同直径的聚丙烯腈(PAN)纤维膜,并对纤维膜在不同流速下进行了水力渗透实验.采用Darcy定理对水力渗透系数进行分析计算;并对膜压缩过程进行分析,利用Happel方程来分析计算纤维膜孔隙率的变化.分析表明.纤维膜水力渗透系数与水的流速、纤维丝直径、膜的孔隙率等因素有关.随流速增加,纤维膜承受压力增加,纤维发生滑移导致纤维丝之间由点接触变为面接触,同时纤维发生变形,孔隙率降低,水力渗透系数降低.纤维丝直径越大,孔隙率越小,水力渗透系数越大;相同流速下渗透压越小,孔隙率和水力渗透系数变化量越大.

Polyacrylonitrile（PAN）fibrous membranes with various fiber diameters were fabricated by electrospinning.The hydraulic permeability with various flow velocities was tested on the lab scale unit and analyzed based on Darcy′s theory and Happel′s model.The relations between fiber diameter,porosity,flow rate,and compressibility were studied.The results indicated that the electrospun membranes experience an increase of fiber diameter and decreases of porosity and hydraulic permeability with the increase of the flow velocity.This was due to the increasing fiber slippage and fiber-fiber contact at a higher pressure by the flow-induced compression.The hydraulic permeability and porosities of the PAN membranes with smaller fiber diameters were smaller than that of the membranes with greater fiber diameters over the range of test pressures.