Surface modification and characterization of highly dispersed silica nanoparticles by a cationic surfactant

The surface of silica nanoparticle was modified with cationic surfactant cetyltrimethylammonium bromide (CTAB), and the different experiment conditions including the amount of surfactant as well as the modification temperature has been studied. Based on the zeta potential plot of unmodified silica, the optimal conditions and possible mechanism for the surface modification of silica nanoparticles was discussed. Thermo gravimetric analysis (TGA) was used for the quantitative measurement of the hydroxyl groups on the silica particles. Brunauer–Emmett–Teller procedure (BET) and Fourier transform-infrared (FT-IR) were also used to investigate the specific surface area and the functional groups on the silica nanoparticle, respectively. The scanning electron microscopy (SEM) results showed a better dispersed state of silica nanoparticles after modifying their surface.