ZnO Nanoparticle Functionalization by Organosilanes Catalyzed with Ethylene Diamine for Production of Stable Nanodispersions in Water

A simple method that was used to obtain stabilized ZnO nanoparticles and their dispersions in water is presented. It yields anisotropic (trigonal prismatic) nanocrystals with dimensions below 50 nm. The Partial Profile Relaxation (PPR) technique was applied in the analysis of X-ray diffraction data with complex anisotropic broadening. Ethylene diamine catalyzed silanization was utilized for the covalent surface functionalization, which allowed us to obtain stable waterborne dispersions when aminosilanes were used. The difference in the surface structure of ZnO nanoparticles for different variants of functionalization was investigated by ²⁹Si NMR spectroscopy. The combination of X-ray diffraction and dynamic light scattering data indicates minimal degree of particle agglomeration in the dispersions.