Crosslinked polymeric nanocapsules from polymer brushes grafted silica nanoparticles via surface-initiated atom transfer radical polymerization

The crosslinked polymeric nanocapsules with inner diameter of about 20–50 nm were prepared successfully by the post-treatment of the poly(methyl acrylate) (PMA) brushes grafted silica nanoparticles (SN-PMA) produced with the surface-initiated atom transfer radical polymerization (SI-ATRP) technique. The PMA chains grafted were modified with amino groups by being treated with ethanediamine (EDA). Then the silica nanoparticles (SN) templates were removed by being etched with hydrofluoric acid (HF) to produce the crosslinked polymeric nanocapsules after the aminated poly(methyl acrylate) (APMA) chains on the SN templates were crosslinked with hexamethylene diisocyanate (HDI). Transmission electron microscopy (TEM) analyses were used to estimate the size of the polymeric nanocapsules.