Recent advances in high-performance TFC membranes: A review of the functional interlayers

The development of interfacial polymerization (IP) technique has revolutionarily changed our methods for water treatment and desalination. Over decades, researchers have devoted their efforts to further improve this marvelous technology through versatile approaches such as optimizing chemical compositions, improving membrane structures and reducing the thickness of selective layers. Recently, constructing interlayers on a support membrane is proven to be a powerful tool to mediate the IP kinetics, which facilitates the formation of thinner polyamide (PA) layers with desired nanostructures. Decreased permeation resistance based on thinner PA layer and enhanced permeable area derived from nanostructures synergistically bring the membrane permeability to an unprecedented height. In this review, we will comprehensively analyze these up-to-date works to discuss the functions of different interlayers from material composition, fabrication methods and designed applications. An empirical relationship between interlayer building materials (chemical composition and dimensionality on a nanoscale) and initial membrane performances (permeability and selectivity) will be established to give inspirations to future works.