A method for characterizing membranes during nanofiltration at extreme pH
A method for characterizing membranes during nanofiltration at extreme pH
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DOI：
10.1016/j.memsci.2010.07.025
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发表时间：
2010-11-01
影响因子：
9.5
通讯作者：
Wessling, Matthias
中科院分区：
文献类型：
--
作者：
Dalwani, Mayur;Benes, Nieck E.;Wessling, Matthias
本工作提出了一种方法，截留分子量（MWCO）表征纳滤膜，在广泛的酸性和碱性环境。聚乙二醇（PEG）已被鉴定为在所关注的苛刻条件下具有足够化学稳定性的合适标记分子。使用凝胶渗透色谱法（GPC）分析PEG分子量分布。为了允许定量GPC分析，提出了一种方案，以克服GPC洗脱图中的重叠盐峰的问题。将该方法应用于众所周知的商业纳滤膜（NF-270. DOW FILMTEC（TM））在pH 2-12范围内。该膜在酸性环境和中性条件下具有相似的MWCO（类似于270 g mol（-1））和渗透性（类似于10 L m（-2）h（-1）bar（-1））。在pH =12时，观察到MWCO（类似于380 g mol（-1））和渗透率（类似于12 Lm（-2）h（-1）bar（-1））的可逆增加。这证明了我们的方法在相关条件下观察纳滤期间MWCO随pH变化的增加值。(C)2010 Elsevier B. V.保留所有权利。
This work presents a method for molecular weight cut off (MWCO) characterization of nanofiltration membranes, in a broad range of acidic and alkaline environments. Polyethylene glycols (PEG) have been identified as suitable marker molecules with sufficient chemical stability under the harsh conditions of interest. PEG molecular weight distributions have been analyzed using gel permeation chromatography (GPC). To allow quantitative GPC analysis, a protocol is presented to overcome the problem of an overlapping salt peak in the GPC elugram. The method is applied to a well-known commercial nanofiltration membrane (NF-270. DOW FILMTEC(TM)) in the pH range 2-12. This membrane has similar MWCO (similar to 270g mol(-1)) and permeance (similar to 10 L m(-2) h(-1) bar(-1)) in acid environment and at neutral conditions. At pH =12 a reversible increase was observed for the MWCO (similar to 380g mol(-1)) and the permeance (similar to 12 Lm(-2) h(-1) bar(-1)). This demonstrates the added value of our method to observe the change of MWCO as a function of pH during nanofiltration at the relevant conditions. (C) 2010 Elsevier B.V. All rights reserved.