Enhancing the Dye-Rejection Efficiencies and Stability of Graphene Oxide-Based Nanofiltration Membranes via Divalent Cation Intercalation and Mild Reduction.

Laminar graphene oxide (GO) membranes have demonstrated great potential as next-generation water-treatment membranes because of their outstanding performance and physicochemical properties. However, solute rejection and stability deterioration in aqueous solutions, which are caused by enlarged nanochannels due to hydration and swelling, are regarded as serious issues in the use of GO membranes. In this study, we attempt to use the crosslinking of divalent cations to improve resistance against swelling in partially reduced GO membranes. The partially reduced GO membranes intercalated by divalent cations (i.e., Mg2+) exhibited improved dye-rejection efficiencies of up to 98.40%, 98.88%, and 86.41% for methyl orange, methylene blue, and rhodamine B, respectively. In addition, it was confirmed that divalent cation crosslinking and partial reduction could strengthen mechanical stability during testing under harsh aqueous conditions (i.e., strong sonication).

Antiviral Nanomaterials for Designing Mixed Matrix Membranes.

Membranes are helpful tools to prevent airborne and waterborne pathogenic microorganisms, including viruses and bacteria. A membrane filter can physically separate pathogens from air or water. Moreover, incorporating antiviral and antibacterial nanoparticles into the matrix of membrane filters can render composite structures capable of killing pathogenic viruses and bacteria. Such membranes incorporated with antiviral and antibacterial nanoparticles have a great potential for being applied in various application scenarios. Therefore, in this perspective article, we attempt to explore the fundamental mechanisms and recent progress of designing antiviral membrane filters, challenges to be addressed, and outlook.