Grafting of temperature sensitive PNIPAAm on hydrophilised polysulfone UF membranes
Grafting of temperature sensitive PNIPAAm on hydrophilised polysulfone UF membranes
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DOI：
10.1016/j.memsci.2007.10.038
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发表时间：
2008-03-05
影响因子：
9.5
通讯作者：
Nystrom, Marianne
中科院分区：
文献类型：
--
作者：
Hesampour, Mehrdad;Huuhilo, Tiina;Nystrom, Marianne
将聚（N-异丙基丙烯酰胺）（PNIPAAm）接枝到聚砜超滤膜上。测定了接枝膜和未改性膜在23 ℃和60 ℃之间的渗透性变化以及PEG（35 kg/mol）和葡聚糖（500 kg/mol）的保留。结果表明，在所测温度范围内，未改性膜的粘度校正水渗透率和溶质截留率基本不变，接枝膜的渗透率随温度升高而增加，葡聚糖和PEG的截留率随温度升高而降低。由于PNIPAAm的低临界溶解温度（LCST），对于改性膜，在27-37 ℃的温度范围内变化最明显。通过SEM和FTIR分析了PNIPAAm在膜内和膜表面的位置和分布。FTIR光谱的深度剖面计算表明，PNIPAAm主要是放置在膜内（在1.06-1.10 μ m的深度从表面），而不是在表面上。接枝PNIPAAm的量较低，对膜的形态没有显著影响。因此，在改性和未改性的膜的SEM照片中看不到差异。与未改性的膜相比，改性的膜表现出明显不同的热响应。(C)2007 Elsevier B. V.保留所有权利。
Poly(N-isopropyl acrylamide) (PNIPAAm) was grafted on a polysulfone UF membrane. The changes of permeability as well as retention of PEG (35 kg/mol) and Dextran (500 kg/mol) between 23 and 60 degrees C were determined for both grafted and unmodified membranes. The results showed that the viscosity corrected water permeability and solute retention were almost constant for the unmodified membranes within the measured temperature range, the permeability of the grafted membranes increased and the retention of Dextran and PEG decreased with temperature. The variation of changes was most obvious in the temperature range 27-37 degrees C for the modified membranes due to the lower critical solution temperature (LCST) of PNIPAAm. The location and profile of PNIPAAm inside and on the surface of the membrane were analysed by SEM and FTIR. Depth profile calculation for FTIR spectra showed that PNIPAAm was mostly placed inside the membrane (at a depth of 1.06-1.10 mu m from the surface) rather than on the surface. The amount of grafted PNIPAAm was low and did not significantly affect the morphology of the membrane. Therefore, a difference in SEM pictures of modified and unmodified membranes could not be seen. The modified membrane exhibited a clearly different thermal response compared to the unmodified one. (C) 2007 Elsevier B.V. All rights reserved.