Solvent nanofiltration through high permeability glassy polymers: Effect of polymer and solute nature
Solvent nanofiltration through high permeability glassy polymers: Effect of polymer and solute nature
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DOI：
10.1016/j.memsci.2012.07.026
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发表时间：
2012-12
影响因子：
9.5
通讯作者：
S. Tsarkov;V. Khotimskiy;Peter M. Budd;V. Volkov;J. Kukushkina;A. Volkov
中科院分区：
文献类型：
--
作者：
S. Tsarkov;V. Khotimskiy;Peter M. Budd;V. Volkov;J. Kukushkina;A. Volkov
研究了溶质性质对PTMSP、PMP和PIM-1膜材料在乙醇介质中截留性能的影响。以PMP和PIM-1为例，研究表明，无论初始气体透过率如何，膜溶胀都能增强溶剂在膜中的传递。无论聚合物性质如何，所有聚合物对低分子量染料(350 Da)都表现出相同的助留率水平和顺序；特别是中性染料溶剂Blue 35对PTMSP、PMP和PIM-1的负助留率分别为：−17%、−11%和−4%。这种保留行为是由于高度的染料-膜相互作用和相当大小的溶质(Vcalc=685ä3)和聚合物中可用的自由体积元素(5-12ä)所引起的“阻塞效应”。染料保留率的提高归因于溶质-膜相互作用的减弱；例如，PIM-1：溶剂蓝35(K=1107；|δPIM−1−δ溶质|=4.2)<；藏红O(K=47.0；|δPIM−1−δ溶质|=6.1)<；橙色II(K=3.3；|δPIM−1−δ溶质|=9.7)。较高分子量溶质的保留主要受自由体积大小的限制。因此，可以通过适当选择聚合物来控制纳滤参数，而高渗透性玻璃聚合物的化学性质的多样性在耐溶剂性和进一步的改性(如交联剂)方面提供了额外的灵活性。提出了PIM-1作为一种对溶解中性化合物具有选择性的聚合物吸附剂的新的可能应用。
The effect of solute nature on the retention performance of membrane materials based on PTMSP, PMP and PIM-1 has been investigated in ethanol media. Using the examples of PMP and PIM-1, it was shown that membrane swelling could enhance the solvent transport across the membrane, regardless of the initial gas permeability. All polymers show the same level and order of retention for low molecular weight dyes (350Da) regardless of the difference in polymer nature; in particular, negative retention of the neutral dye Solvent Blue 35 was observed for PTMSP, PMP and PIM-1: −17%, −11% and −4%, respectively. This retention behavior was explained by a “blocking effect” due to high dye-membrane interaction and comparable size of the solute (Vcalc=685Å3) and available free volume elements within the polymer (5–12Å). An increase of dye retention is attributed to a decrease of solute-membrane interaction; for example, PIM-1: Solvent Blue 35 (K=1107; |δPIM−1−δsolute|=4.2)<Safranine O (K=47.0; |δPIM−1−δsolute|=6.1)<Orange II (K=3.3; |δPIM−1−δsolute|=9.7). The retention of higher molecular weight solutes is expected to be limited mainly by free volume size. Thus, it is possible to control nanofiltration parameters by proper selection of the polymer and the variety in the chemical nature of high permeability glassy polymers provides additional flexibility in solvent resistance and further modifications (e.g. cross-linking). A new possible application of PIM-1 as a polymeric sorbent with selectivity towards dissolved neutral compounds is proposed.