共混改性法制备高性能聚砜温敏膜

Preparation of thermo-responsive polysulfone membranes with satisfactory performance via blending modification method

以聚N异丙基丙烯酰胺(PNIPAM)微球同时作为致孔剂和温度响应型智能开关,采用共混改性和蒸气诱导相分离(VIPS)法有效调控聚砜膜微观结构和PNIPAM微球分布,成功制备了高性能的聚砜温敏膜.通过扫描电镜、衰减全反射红外光谱、接触角和水通量测试等手段,研究了VIPS过程中蒸气暴露时间(tv)对聚砜温敏膜的微观结构、化学成分、亲疏水性、跨膜水通量以及温度响应性的影响.结果表明,随着tv的增加,温敏膜表面由致密变多孔,断面结构由指状孔结构转为双连续结构,高低温跨膜水通量逐步增加,但温度响应性先增大后减小.当tv为20 s时,聚砜温敏膜具有最佳温度响应性,其归一化温度响应开关系数(N)高达18.6±4.6,39℃下的水通量为25443 L/(m^2·h·MPa),且具有较好的稳定性和可逆性.

Thermo-responsive polysulfone membranes with satisfactory performance were successfully prepared by efficient regulating microstructure of PSf membranes and the distribution of poly(N-isopropylacrylamide)(PNIPAM)microgels,which simultaneously acted as pore-forming additives and thermo-sensitive gates,via blending modification and vapor-induced phase separation(VIPS)method.The effects of the exposure time during the VIPS process(tv)on the microstructure,chemical composition,wettability,trans-membrane water flux and thermo-responsive characteristics of thermo-responsive polysulfone membranes were investigated by means of scanning electron microscope,attenuated total reflectance fourier transform infrared spectroscopy,contact angle and water flux tests.The results showed that with the increase of tv,the surface of thermo-responsive polysulfone membranes changed from dense to porous,and cross-sectional structures changed from finger-like structures to bi-continuous structures.The trans-membrane water fluxes at both low and high temperatures increased gradually,while the thermo-responsive properties increased first and then decreased.The thermo-responsive polysulfone membrane prepared by the tv of 20 s possessed the optimized thermo-responsive characteristics.The normalized thermo-responsive gating coefficient(N)was as high as 18.6±4.6,and the water flux at 39℃was 25443 L/(m^2·h·MPa),which had satisfactory stability and repeatability.