The Preparation Of Monodisperse Hybrid Core-Shell Particles With SiO₂, TiO₂

In recent years, the organic-inorganic nanocomposites of growing concern by the researchers. The structural design and controllable preparation of hybrid nanomaterials for the purpose of obtaining expectant properties is a focus of research in materials science. Hybrid nanomaterials can display the advantages of each component, furthermore give significant play to their cooperative advantages due to the hybridization between their components. Hybrid nanomaterials hence have varied functions and can be used for both constructional materials and function materials, and have a vast range of prospects for applying. The size of uniform spherical nano-composite materials is expected to also because of its self-assembly, photonic crystals, biological testing, and other aspects of the broad application of the experiment aroused great interest in the research . This paper used soap-free emulsion polymerization methods and Sol-gel material prepared the core-shell structure of the silica/PMMA, PS/Titania narrow distribution microspheres . And on this basis, has been with core-shell-shell narrow distribution of organic-inorganic-organic composite microspheres.The studies and the results are as follows:1: Methyl methacrylate (MMA) or styrene (St) as the monomer, in the 2,2'-Azobis (2-methylpropionamide)(AIBA) or potassium sulfate (KPS) as initiator, use soap-free emulsion polymerization methods, respectively, the polymethyl methacrylate (PMMA) and polystyrene (PS) microspheres with narrow distribution polymer particle in diameter of 200-400 nm obtained. On to AIBA as the initiator of the latex microspheres surface with positive charge, and to KPS as the initiator of the latex microspheres surface with negatively charged.2: Herein, we describe a new approach to generate polymer coated inorganic capsules. Monodispersed silica-polymer core-shell nanospheres were prepared by soap-free emulsion polymerization. To coat the cores by polymer, silica nanoparticles were modified by 3-(trimethoxysilyl) propyl methacrylate (MPS). The thicknesses of polymer shells were found to be dependent on the amount of monomer and grafted silica nanoparticles. The formation mechanism of SiO2-PMMA core-shell nanoparticles was speculated. This method used for the preparation of core-shell particles is simple, and therefore advantageous over traditional emulsion polymerization methods.3: Herein, we describe a new approach to generate inorganic coated polymer nanospheres. The key is to use a sulfonation polystyrene particles with absorbed water as templates that allow an inward diffusion and growth of the precursor inorganic materials inside the gel particle. The desired the thickness of the inorganic shell are determined by a one step sol-gel process. The core template particles were synthesized by an sulfonation of polystyrene particles with concentrated sulfuric acid. The monodispersity of the sulfonation polystyrene particles was ensured by synchronous sulfonation and soap-free emulsion polymerization.4: Herein, we describe a new approach to generate polymer coated inorganic-organic nanoparticles. Monodispersed core-shell-shell nanoparticles were prepared by soap-free emulsion polymerization. To coat the core-shell nanoparticles by polymer, TiO2 coated core-shell nanoparticles were modified by MPS. The thicknesses of polymer shells were found to be dependent on the amount of monomer and grafted core-shell nanoparticles. This method used for the preparation of core-shell-shell particles is simple, and therefore advantageous over traditional emulsion polymerization methods.The produces were characterized by scanning electron microscopy (SEM), Transmission Electron Microscopy(TEM), Fourier transform-infrared spectrometer (FT-IR), Thermogravimetric Analysis (TGA), and Dynamic Light Scattering(DLS).