Synthesis and characterization of core/shell titanium dioxide nanoparticle/polyacrylate nanocomposite colloidal microspheres

Abstract

Core/shell titanium dioxide (TiO2) nanoparticle/poly(methyl methacrylate-butyl acrylate-methacrylic acid) [P(MMA-BA-MAA)] nanocomposite colloidal microspheres have been successfully synthesized via in situ emulsion polymerization. TiO2 nanoparticles were firstly modified by silane coupling agent, vinyl triethoxysilane (A-151), to increase the dispersibility of TiO2 nanoparticles into the polyacrylate matrix. The A-151-modified TiO2 nanoparticles were characterized by Fourier transform infrared spectra (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and transmission electron microscopy (TEM) techniques. The synthesized nanocomposite colloidal microspheres were characterized by TEM, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), and differential scanning calorimetry analysis (DSC). The results showed that A-151 coupling molecules was chemically bonded on the TiO2 nanoparticles surface, and the amount of coated A-151 was 3.0 wt%. According to TEM micrographs and DLS results, the dispersibility of modified TiO2 nanoparticles was obviously improved. TEM analysis revealed that an obvious core/shell structure morphology was observed with the core TiO2 particles surrounded by a uniform 10∼15-nm thick polymer shell. SEM–EDS result showed that TiO2 nanoparticles were homogenously monodispersed in the polymer matrix. DSC measurements indicated a glass transition temperature (T g) enhancement of P(MMA-BA-MAA).