Water pollution is a major global challenge, as conventional polymeric membranes are not adequate for water treatment anymore. Among emerging materials for water treatment, composite membranes are promising, as they have simultaneously improved water permeation and ions rejection. Recently, a new family of 2D materials called MXenes has attracted considerable attention due to their appealing properties and wide applications. MXenes can be incorporated into many polymeric materials due to their high compatibility. MXenes/polymer composite membranes have been found to have appealing electrical, thermal, mechanical, and transport properties, because of strong interactions between polymer chains and surface functional groups of MXenes and the selective nanochannels that are created. This article reviews advances made in the area of ion‐selective MXene‐based membranes for water purification. It puts the advances into perspective and provides prospects. MXenes’ properties and synthesis methods are briefly described. Strategies for the preparation of MXene‐based membranes including mixed‐matrix membranes, thin‐film nanocomposite membranes, and laminated membranes are reviewed. Recent advances in ion‐separation and water‐desalination MXene‐based membranes are elucidated. The dependence of ion‐separation performance of the membranes on fabrication techniques, MXene's interlayer spacing, and MXene's various surface terminations are elucidated. Finally, opportunities and challenges in ion‐selective MXene‐based membranes are discussed.
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.
more » « less- Award ID(s):
- 2045336
- NSF-PAR ID:
- 10365396
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Polymer Science
- Volume:
- 59
- Issue:
- 21
- ISSN:
- 2642-4150
- Page Range / eLocation ID:
- p. 2581-2589
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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