Biomimetic synthesis of copolymer–silica nanoparticles with tunable compositions and surface property

Abstract

We report using cationic poly(acrylamide- co-2-(dimethylamino) ethyl methacrylate, methyl chloride quaternized) (poly(AM- co-DMC)) to mediate biomimetic synthesis of hybrid copolymer–silica nanoparticles under ambient conditions. Poly(AM- co-DMC)s with various mole contents of DMC were prepared by solution copolymerization in water. Silicification was achieved by simply stirring a mixture of tetramethyl orthosilicate and an aqueous poly(AM- co-DMC) solution at room temperature for 30 min. Copolymers–silica hybrid nanoparticles were characterized with transmission electron microscopy (TEM), FT-IR spectroscopy, 1H NMR, thermogravimetry and aqueous electrophoresis. TEM studies indicated that the hybrid nanoparticles have well-defined spherical morphology and relatively narrow polydispersity with diameters of less than 50 nm. The compositions and zeta potentials of hybrid nanoparticles could be controlled by simply adjusting compositions of copolymers and solution conditions for silica mineralization. Due to the tunable compositions and surface zeta potentials, these new particles would be expected to have potential applications for controlled delivery, therapeutics and bioimaging.