聚碳酸酯/醋酸纤维素共混超滤膜的制备与性能

Preparation and properties of polycarbonate / cellulose acetate blend ultrafiltration membrane

摘要:

以聚碳酸酯（PC）为基础超滤膜材料，聚乙烯比咯烷酮为致孔剂，将其与醋酸纤维素（CA）共混后，使用浸没沉淀相转化法制备了一系列聚碳酸酯/醋酸纤维素共混超滤膜（CPCM）。通过FTIR、WAC、SEM、孔隙度和平均孔半径对纯聚碳酸酯超滤膜（PCM）和CPCM进行了表征，考察了制备条件对膜性能的影响。结果表明，CA成功地与PC共混；随着CA的添加量增大，CPCM的指状孔通道层逐渐变厚，空腔变大，致密层的孔洞变大，孔道之间连通孔增多；未添加CA的PCM平均孔半径为23.33 nm，添加了2 wt% CA的CPCM平均孔半径为42.53 nm，比PCM增大了82.3%。CPCM的纯水通量远高于PCM，最高达357.7 L?m-2?h-1。牛血清蛋白（BSA）截留率相较于PCM膜略有降低，但仍在95%以上。综合CPCM的纯水通量、BSA截留率、通量恢复率（FRR）结果，当CA添加量为1 wt%时综合性能最好，纯水通量Jw为334.3 L?m-2?h-1，BSA截留率R为95.9%，两轮FRR值分别为84.8%、76.7%。添加CA显著提升了PC膜表面的亲水性，从而增强了其超滤性能。

Abstract:

A series of polycarbonate (PC) / cellulose acetate (CA) blend ultrafiltration membranes (CPCM) were prepared by immersion precipitation phase inversion method using PC as the basic ultrafiltration membrane material and polyvinylpyrrolidone as the pore-forming agent. Polycarbonate ultrafiltration membrane( PCM )and CPCM were characterized by FTIR, WAC, SEM, porosity and average pore radius. The effects of preparation conditions on the performances of membranes were investigated. The results showed that CA was successfully blended with PC. With the increase of CA content, the finger-like pore channel layer of CPCM gradually became thicker, the cavity became larger, the pores in the dense layer became larger, and the connected pores between the pores increased. The average pore radius of PCM without CA was 23.33 nm, and the average pore radius of CPCM with 2 wt% CA was 42.53 nm, which was 82.3% over that of PCM without CA. The pure water flux of CPCM was much higher than that of PCM, up to 357.7 L?m-2?h-1. The BSA rejection was slightly lower than that of PCM membrane, but it was still above 95%. Based on the results of pure water flux, bovine serum albumin (BSA) rejection rate and flux recovery rate (FRR) of CPCM, the comprehensive performances were the best when the addition amount of CA was 1 wt %. The pure water flux Jw was 334.3 L?m-2?h-1, the BSA rejection rate R was 95.9 %, and the two rounds of FRR values were 84.8 % and 76.7 %, respectively. The addition of CA significantly improved the hydrophilicity of the PC membrane surface, thereby enhancing its ultrafiltration performance.