Layer-by-Layer Assembled Nanocomposite Membranes with Functionalized Dendritic Mesoporous Silica Nanoparticles for Selective Heavy Metal Removal

This study focuses on the synthesis and surface functionalization of dendritic mesoporous silica nanoparticles (DMSNs) to enhance the efficiency of nanocomposite membranes for water purification. DMSNs were successfully synthesized and functionalized with amine and polymer groups to improve their integration into chitosan-polysulfone (CHIT-PSf) membranes. A layer-by-layer (LbL) assembly approach was employed to fabricate the nanocomposite membranes, ensuring uniform distribution of the functionalized DMSNs within the membrane matrix. The incorporation of functionalized DMSNs markedly enhanced the membranes' hydrophilicity, permeability, and antifouling and heavy metal rejection. Physicochemical characterization confirmed the successful synthesis and functionalization of DMSNs and their beneficial impact on membrane properties. Performance tests showed that the CHIT-DMSN-NH₂ membrane achieved a high water permeability of 3.2 ± 0.1 L/m²·h·bar and a rejection rate of 95 ± 2% for Co, Ni, Pb, Cu, and Cd ions. Furthermore, antifouling evaluations demonstrated a 100% flux recovery ratio, indicating excellent fouling resistance. These findings highlight the potential of functionalized DMSNs in enhancing membrane performance, making them promising candidates for advanced water treatment applications. This study provides valuable insights into the development of high-performance nanocomposite membranes with improved separation efficiency and long-term stability.