Preparation of silver nanoparticle immobilized fibrillar silicate by poly(dopamine) surface functionalization

Surface modified fibrillar silicate (FS) was prepared by dopamine oxide polymerization and self-assembly of poly(dopamine) (PDA) on the FS surface, presynthesized silver nanoparticles subsequently adhered to the PDA functionalized FS (FS-PDA) surface by simply dipping FS-PDA in silver nanoparticles solution, owing to the metal-binding ability of catechol and nitrogen-containing groups on the PDA coating on the surface of FS. The chemical composition of the modified FS surface was determined by X-ray photoelectron spectroscopy. Surface morphological changes of the FS nanofibers were observed by transmission electron microscopy. The results indicated that the in situ spontaneous oxidative polymerization of dopamine on the FS surface and the immobilization of Ag nanoparticles on the surface of FS were successful. The FS-PDA/Ag demonstrated a significant enhancement in antibacterial properties compared to the pristine FS by using Escherichia coli as model strain.