Mechanically robust hydrophobized double network hydrogels and their fundamental salt transport properties
Mechanically robust hydrophobized double network hydrogels and their fundamental salt transport properties
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DOI：
10.1002/pol.20210260
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发表时间：
2021-07-26
影响因子：
3.4
通讯作者：
Page，Zachariah A.
中科院分区：
文献类型：
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作者：
Allen，Marshall J.;Sujanani，Rahul;Page，Zachariah A.
水溶胀的聚合物网络对于从组织再生到水净化的应用范围是有吸引力的。对于水净化，带电聚合物提供优异的离子分离性能。然而，许多离子交换膜（IEM）是脆性的，需要使用厚的支撑材料，这最终降低了通量。为此，新的双网络水凝胶（DNHs）与可变的水含量的制备和其特征在于在机械和离子传输性能，以评估其潜在的效用作为坚韧膜材料。第一个网络含有固定的阴离子电荷，而另一个是由具有不同比例的疏水性丙烯酸乙酯（EA）和亲水性二甲基丙烯酰胺（DMA）重复单元的共聚物组成。独立式DNH膜的表征揭示了相对于100%DMA，95%/5%EA/DMA的水含量从88重量%减少到53重量%，并且极限应力和应变分别同时增加~3.5倍和~4.5倍。与水净化相关的基本盐传输特性，包括渗透率，溶解度和扩散率，测量和系统地与传统的膜材料相比，通知DNH膜应用的发展。同时降低水含量和增加机械完整性的能力突出了DNH作为未来膜应用的合成平台的潜力。
Water swollen polymer networks are attractive for applications ranging from tissue regeneration to water purification. For water purification, charged polymers provide excellent ion separation properties. However, many ion exchange membranes (IEMs) are brittle, necessitating the use of thick support materials that ultimately decrease throughput. To this end, novel double network hydrogels (DNHs) with variable water content are prepared and characterized in terms of mechanical and ion transport properties to evaluate their potential utility as tough membrane materials. The first network contains fixed anionic charges, while the other is comprised of a copolymer with varied ratios of hydrophobic ethyl acrylate (EA) and hydrophilic dimethyl acrylamide (DMA) repeat units. Characterization of freestanding DNH films reveals a reduction in water content from 88 to 53 wt% and a simultaneous increase in ultimate stress and strain by ~3.5× and ~4.5×, respectively, for 95%/5% EA/DMA, relative to 100% DMA. Fundamental salt transport properties relevant to water purification, including permeability, solubility, and diffusivity, are measured and systematically compared with conventional membrane materials to inform the development of DNHs for membrane applications. The ability to simultaneously reduce water content and increase mechanical integrity highlights the potential of DNHs as a synthetic platform for future membrane applications.