(380m) Modified Ultrathin Membranes Composed of Graphene Oxide for Gas Separation

In recent times, there has been a growing focus on membrane-based separation technologies due to their various benefits, such as reduced energy consumption, simplified operation, and environmental friendliness. In theory, membranes crafted from 2D materials can be as thin as a single atom, minimizing transport resistance and maximizing permeation flux. Nano- or sub-nanometer apertures, derived from inherent porous structures, precise perforation, or controlled assembly of 2D materials, enable highly selective transport of liquids, gases, ions, and other species through these membranes. Graphene oxide (GO), a derivative of graphene within the 2D material family with single-atomic-thick structure, offers advantages such as a high aspect ratio of its flakes and superior dispersibility in solvents, attributed to its oxygen-containing functional groups. These characteristics render GO well-suited for solution-based deposition processes in fabricating membranes comprised of stacked 2D materials. While graphene oxide lamellar membranes have demonstrated remarkable efficacy in water treatment, advancements in their application for gas purification have been comparatively limited. The instability and absence of precise control over in-plane defects within 2D flakes diminishes GO's efficacy in separation processes. Currently, despite endeavors to tackle specific facets, there are no technologies or methodologies capable of holistically resolving these challenges. Molecular Layer Deposition (MLD) and Atomic Layer Deposition (ALD) represent state-of-the-art techniques aimed at addressing all aforementioned issues. MLD and ALD are a vapor phase deposition technique that involves self-limiting surface reaction carried out sequentially in a repeated manner. Both MLD and ALD are methods for growing thin films with precise control over thickness and composition at the atomic or molecular scale. The resulting deposition would be expected to take place preferentially at the edges of GO flakes and might fill the gaps at the edges between laterally adjacent flakes, and it can tune the pore size of in-plane defects for molecular sieving.