Engineering composite membrane architecture via ultrasonic spray coating: Interlayered organosilica structures for efficient molecular separation

Bridged organosilicas hold significant potential for high-performance molecular separation membranes. However, the development of ultrathin, defect-free, and spatially uniform organosilica separation layers on porous substrates remains an ongoing challenge. In this study, a new strategy is proposed for fabricating organosilica membranes with graphene oxide (GO) as a functional interlayer, using an efficient ultrasonic atomization spray-coating technique. By optimizing the interlayer architecture and fabrication parameters, ultrathin BTESE-derived organosilica selective layers were successfully constructed on GO-coated polyacrylonitrile (PAN) nanofibrous substrates under mild processing conditions. The resulting composite membranes were evaluated for separation of organic dyes. The optimized membrane demonstrated high dye rejection (>96 %) and good long-term stability during continuous nanofiltration operation. This work not only presents a straightforward method for the production of high-quality organosilica composite membranes but also offers new insights into the design of high-performance nanofiltration materials.