Synthesis and characterization of thin film nanocomposite forward osmosis membrane with hydrophilic nanocomposite support to reduce internal concentration polarization
Synthesis and characterization of thin film nanocomposite forward osmosis membrane with hydrophilic nanocomposite support to reduce internal concentration polarization
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DOI：
10.1016/j.memsci.2013.08.014
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发表时间：
2014-01-01
影响因子：
9.5
通讯作者：
Rahbari-Sisakht, M.
中科院分区：
文献类型：
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作者：
Emadzadeh, D.;Lau, W. J.;Rahbari-Sisakht, M.
考虑到正向渗透(FO)膜面临的最大挑战之一是内部浓差极化(ICP)，通过在聚砜(PSI)衬底中掺入不同含量的纳米二氧化钛(TiO2)(从0到0.90wt%)来制备薄膜纳米复合(TFN)膜，以降低ICP。用不同的方法对所制备的纳米复合基板的亲水性、总孔隙率、表面粗糙度和横截面形貌进行了表征。结果表明，纳米二氧化钛的加入增加了基材的亲水性和孔隙率。此外，随着纳米二氧化钛负载量的增加，形成了大量的指状大孔洞，从而提高了材料的透水性。在AL-FS取向下，以DL水为原料，以0.5M的氯化钠为牵伸溶液，制备的TFN膜的水通量为18.81 L/m(2)h，Le。TFC膜的反向溶质通量无明显变化，比未掺入TiO2时的TFC膜高97%。与对照TFC膜相比，以海水为料液，以2MNaC l为牵伸溶液，TFN0.60膜的FO水通量从4.2M/m(2)h(AL-FS取向)和6.9 L/m(2)h(AL-DS取向)显著增加。水通量的增加可以归因于结构参数的降低(S值=0.39 mm)，主要是由于形成了连接LOP和衬底底层的指状大空洞，减少了弯曲程度，导致电感耦合系数降低。虽然进一步增加二氧化钛纳米粒子的负载量到0.90wt%可以增加膜的透水性，但反溶质通量的显著增加会损害FO的性能。据作者所知，这是第一个将PSF-Ti02纳米复合衬底用于FO的TFN膜的报道。(C)2013爱思唯尔B.V.保留所有权利
Realizing that one of the most important challenges in the forward osmosis (FO) membrane is internal concentration polarization (ICP), thin film nanocomposite (TFN) membranes were prepared by incorporating different loadings of titanium dioxide (TiO2) nanoparticles (ranging from 0 to 0.90 wt%) into the polysulfone (PSI) substrate in order to reduce ICP. The nanocomposite substrates prepared were characterized with respect to hyclrophilicity, overall porosity, surface roughness and cross-sectional morphology by different methods. Results revealed that both hydrophilicity and porosity of the substrate were increased upon addition of TiO2 nanoparticles. Moreover, a large number of finger-like macrovoids were developed by increasing the loading of TiO2 nanoparticles, leading to enhancement in water permeability. As for the FO performance tested at AL-FS orientation and with Dl water as feed and 0.5 M NaCl as draw solution, the TFN membrane prepared using PSI substrate embedded with 0.60 wt% TiO2 nanoparticles (designated as TFN0.60) exhibited the most promising result by showing water flux of 18.81 L/m(2) h, Le. 97% higher than the control TFC membrane prepared by substrate without TiO2 incorporation (designated as TFC), with no significant change in reverse solute flux. Compared to the control TFC membrane, the FO water flux of TFN0.60 was also reported to increase significantly from 4.2 to 8.1 L/m(2) h (AL-FS orientation) and from 6.9 to 13.8 L/m(2)h (AL-DS orientation) when seawater was used as feed solution and 2 M NaCl was used as draw solution. The increase in water flux can be attributed W the decrease in structural parameter (S value = 0.39 mm), mainly due to the formation of finger-liked macrovoids that connect the Lop and bottom layer of the substrate and reduce the tortuosity, resulting in decreased ICP. Although further increasing TiO2 nanoparticles loading to 0.90 wt% could increase membrane water permeability, the FO performance was compromised by a significant increase in reverse solute flux. To the best knowledge of the authors, this is the first report on TFN membrane using PSf-TiO2 nanocomposite substrate for FO applications. (C) 2013 Elsevier B.V. All rights reserved