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18.64.6，39 ºC下的水通量为25443 L/(m2·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 act as pore-forming additives and thermo-sensitive gates, via blending modification and vapor-induced phase separation (VIPS) method. The effect 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 18.64.6, and the water flux at 39 ºC was 25443 L/(m2·h·MPa), which had satisfactory stability and repeatability.

[1]Yoon Y, Kye H, Yang W S, et al. Comparing graphene oxide and reduced graphene oxide as blending materials for polysulfone and polyvinylidene difluoride membranes[J]. Appl Sci, 2020, 10(6): 1-10.
[2]Ganesh B M, Isloor A M, Ismail A F. Enhanced hydrophilicity and salt rejection study of graphene oxide-polysulfone mixed matrix membrane[J]. Desalination, 2013, 313: 199-207.
[3]Ma Y X, Shi F M, Wang Z J, et al. Preparation and characterization of PSf/clay nanocomposite membranes with PEG 400 as a pore forming additive[J]. Desalination, 2012, 286: 131-137.
[4]李丽华, 胡朝武, 马明明, 等. 致孔剂对氧化石墨烯改性聚砜复合超滤膜结构和性能的影响[J]. 膜科学与技术, 2016, 36(1): 39-44.
[5]Li X Y, Xie R, Zhang C, et al. Effects of hydrophilicity of blended submicrogels on the microstructure and performance of thermo-responsive membranes[J]. J Membr Sci, 2019, 584: 202-215.
[6]Luo F, Xie R, Liu Z, et al. Smart gating membranes with in situ self-assembled responsive nanogels as functional gates[J]. Sci Rep, 2015, 5: 1-13.
[7]Zhu L J, Song H M, Wang G, et al. Dual stimuli-responsive polysulfone membranes with interconnected networks by a vapor-liquid induced phase separation strategy[J]. J Colloid Interf Sci, 2018, 531: 585-592.
[8]Liu H W, Liao J B, Zhao Y, et al. Bioinspired dual stimuli-responsive membranes with enhanced gating ratios and reversible performances for water gating[J]. J Membr Sci, 2018, 564: 53-61.
[9]Barroso T, Viveiros R, Coelho M, et al. Influence of poly(N-isopropylacrylamide) and poly(N,N′-diethyl acrylamide) coatings on polysulfone/polyacrylonitrile-based membranes for protein separation[J]. Polym Adv Technol, 2012, 23: 1381-1393.
[10]Gao J, Luo P, Yan X Y, et al. Temperature-sensitive poly(N-isopropylacrylamide)-reduced graphene oxide/polysulfone as smart separation membrane: structure and performance[J]. Iran Polym J, 2018, 27: 951-963.
[11]Temtem M, Pompeu D, Barroso T, et al. Development and characterization of a thermoresponsive polysulfone membrane using an environmental friendly technology[J]. Green Chem, 2009, 11: 638-645.
[12]Zhu L J, Song H M, Li C, et al. Surface wormlike morphology control of polysulfone/poly(N-isopropylacrylamide) membranes by tuning the two-stage phase separation and their thermo-responsive permselectivity[J]. J Membr Sci, 2018, 555: 290-298.
[13]王建宇, 徐又一, 易砖, 等. PSF-g-PAA和PSF-g-PNIPAAm的合成及其共混膜的环境响应性研究[J]. 高分子学报, 2009, 11: 1138-1145.
[14]Hesampour M, Huuhilo T, Makinen K, et al. Grafting of temperature sensitive PNIPAAm on hydrophilised polysulfone UF membranes[J]. J Membr Sci, 2008, 310: 85-92.
[15]Luo F, Zhao Q, Xie R, et al. Effects of fabrication conditions on the microstructures and performances of smart gating membranes with in situ assembled nanogels as gates[J]. J Membr Sci, 2016, 519: 32-44.
[16]Venault A, Chang Y, Wang D M, et al. PEGylation of anti-biofouling polysulfone membranes via liquid- and vapor-induced phase separation processing[J]. J Membr Sci, 2012, 403: 47-57.
[17]Venault A, Chang Y. Surface hydrophilicity and morphology control of anti-biofouling polysulfone membranes via vapor-induced phase separation processing[J]. J Nanosci Nanotechno, 2013, 13: 2656-2666.
[18]Kuvarega A T, Khumalo N, Dlamini D, et al. Polysulfone/N,Pd co-doped TiO2 composite membranes for photocatalytic dye degradation[J]. Sep Purif Technol, 2018, 191: 122-133.
[19]Liu Y L, Lin G C, Wu C S. Preparation of polysulfone-g-poly(N-isopropylacrylamide) graft copolymers through atom transfer radical polymerization and formation of temperature-responsive nanoparticles[J]. J Polym Sci Pol Chem, 2008, 46: 4756-4765.
[20]琚正川，陈洁，肖智成. P(NIPAM-DADMAC)微凝胶的合成、表征及药物释放[J]. 同济大学学报, 2003, 31(10): 1256-1260.
[21]Yang M, Chu L Y, Li Y, et al. Thermo-responsive gating characteristics of poly(N-isopropylacrylamide)-grafted membranes[J]. Chem Eng Technol, 2006, 29(5): 631-636.
[22]Li Y, Chu L Y, Zhu J H, et al. Thermoresponsive gating characteristics of poly(N-isopropylacrylamide)-grafted porous poly(vinylidenefluoride) membranes[J]. Ind Eng Chem Res, 2004, 43: 2643-2649.