制备条件对多孔不锈钢中空纤维载体微结构的影响

Effects of preparation condition on microstructure of porous stainless steel hollow fiber substrates

采用相转化法制备不锈钢中空纤维载体,系统考察空气间距、芯液流速和纺丝液中水含量等制备条件对多孔不锈钢中空纤维载体微结构及性能的影响。结果表明,随着空气间距的增加,中空纤维载体海绵层逐渐变薄;随着芯液流速的增加,中空纤维载体截面整体形状逐渐呈规整的圆形载体壁变薄;随着水含量的增加,纺丝液的黏度不断增加,中空纤维载体断面逐渐由典型的“三明治”结构变成双层非对称结构。当空气间距为10 cm、芯液流速为20 mL/min、纺丝液中水质量分数为2%时,其N2渗透性可达1.59×10^(-4) mol/(m^(2)·s·Pa),同时弯曲强度高达238.4 MPa。由此可知,通过对纺丝过程中制备条件的调变,可以实现不锈钢中空纤维载体微结构的有效调控。

Porous stainless steel hollow fiber substrates were prepared by phase transformation method.Effects of preparation condition of air gap,inject rate of internal coagulant and the water content in spinning dope on the performance and microstructure of stainless steel hollow fiber substrates were systematically investigated.Results showed that the sponge layer in hollow fiber substrate became thinner with the increase of air gap.With the increase of inject rate of internal coagulant,the overall shape of hollow fiber substrate cross-section gradually became regular round,and the membrane wall became thinner.With the increase of water content in spinning dope,the viscosity of spinning solution increased and the cross-section of hollow fiber substrate gradually changed from typical“sandwich”structure to double asymmetric structure.When the air gap was 10 cm,the inject rate of internal coagulant was 20 mL/min,and the water mass fraction in the spinning dope was 2%,the as-prepared stainless steel hollow fiber substrates possessed excellent gas permeability(1.59×10^(-4) mol/(m^(2)·s·Pa))and bending strength(238.4 MPa).Thus,the microstructure of stainless steel hollow fiber substrates could be effectively controlled by adjusting the preparation conditions during spinning.