Cation-controlled wetting properties of vermiculite membranes and its promise for fouling resistant oil–water separation
journal contributionposted on 11.05.2020, 10:09 by K Huang, P Rowe, C Chi, V Sreepal, T Bohn, K-G Zhou, Yang Su, E Prestat, P Balakrishna Pillai, CT Cherian, A Michaelides, RR Nair
© 2020, The Author(s). Manipulating the surface energy, and thereby the wetting properties of solids, has promise for various physical, chemical, biological and industrial processes. Typically, this is achieved by either chemical modification or by controlling the hierarchical structures of surfaces. Here we report a phenomenon whereby the wetting properties of vermiculite laminates are controlled by the hydrated cations on the surface and in the interlamellar space. We find that vermiculite laminates can be tuned from superhydrophilic to hydrophobic simply by exchanging the cations; hydrophilicity decreases with increasing cation hydration free energy, except for lithium. The lithium-exchanged vermiculite laminate is found to provide a superhydrophilic surface due to its anomalous hydrated structure at the vermiculite surface. Building on these findings, we demonstrate the potential application of superhydrophilic lithium exchanged vermiculite as a thin coating layer on microfiltration membranes to resist fouling, and thus, we address a major challenge for oil–water separation technology.
Royal Society, Engineering and Physical Sciences Research Council, UK (EP/K016946/1 and EP/N013670/1)
British Council (award reference number 279336045)
European Research Council (contract 679689)
- Aeronautical, Automotive, Chemical and Materials Engineering