Cation-controlled wetting properties of vermiculite membranes and its promise for fouling resistant oil–water separation

Abstract

The surface free energy is one of the most fundamental properties of solids, hence, manipulating the surface energy and thereby the wetting properties of solids, has tremendous potential for various physical, chemical, biological as well as 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 by exploiting this mechanism, vermiculite laminates can be tuned from superhydrophillic to hydrophobic simply by exchanging the cations; hydrophilicity decreases with increasing cation hydration free energy, except for lithium. Lithium, which has a higher hydration free energy than potassium, 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

Study on contact angles and surface energy of MXene films

“…Although some 2D materials are thought to be inherently hydrophilic, their wetting behaviors are oen perturbed by their substrates, contaminants, and intercalated ions, [4][5][6] which can shi the WCA in a wide range. The unintentional contamination at the surfaces causes the scattering values of WCAs for 2D materials, challenging the long-held belief on the wettability of some materials, such as graphene and graphite.…”

Formation of Water-Channel by Propylene Glycol into Polymer for Porous Materials

“…In a recent study, Huang et al have used a porous membrane to resist the fouling effect. The porous membrane was coated with a lithium exchange vermiculite to prevent contamination and used for oil-water separation [17]. Plasticization or cross-linking of additives in a polymer and generation of pores by applying a physical force have been used in the manufacturing of a porous membrane [18].…”

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