Poly(methyl methacrylate)/SiO2(PMMA/SiO2) hybrid composites were prepared via “grafting onto” strategy based on UV irradiation in the presence of iron aqueous solution. Two steps were used to graft polymethyl methacrylate (PMMA) onto the surface of nanosilica, anchoring 3-(methacryloxy) propyl trimethoxysilane (MPTS) onto the surface of nanosilica to modify it with double bonds, and then grafting PMMA onto the surface of nanosilica with FeCl3as photoinitiator. The products were characterized by FT-IR, TGA, TEM, DLS, and XPS. The results showed that it is easy to graft PMMA onto the surface of nanosilica under UV irradiation, and the hybrid particles are monodisperse and have core-shell structure with nanosilica as the core and PMMA layers as the shell. Furthermore, the products initiated by FeCl3have higher monomer conversion, percent grafting, and better monodispersion compared with the products initiated by traditional photoinitiator such as 2-hydroxy-4-(2-hydroxyethoxy)-2-methyl-propiophenone (Irgacure 2959).

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A core–shell fluorine‐containing polyacrylate emulsion was successfully prepared by UV‐initiated seeded emulsion polymerization in two stages in the presence of two photoinitiators. The water‐soluble photoinitiator for the core polymerization and the oil‐soluble photoinitiator was used for the shell polymerization. Both of the two stage polymerizations could be completed within 15 min and displayed a conversion above 94%. The emulsion and the films were characterized by Fourier transformed infrared spectrometry, transmission electron microscopy, dynamic light scattering, X‐ray photoelectron spectroscopy (XPS), contact angle (CA), and thermogravimetry analysis, respectively. The analysis results indicated that the fluorine‐containing latex particles had very small particle size (40 nm) with a core–shell structure and a narrow particle size distribution. XPS analysis revealed that a gradient concentration of fluorine excited in fluorine‐containing emulsion film from the film–air interface to the film–glass interface. In addition, the film formed from the fluorine‐containing emulsion exhibited not only higher thermal stability but also better hydrophobicity than that of the fluorine‐free emulsion. Copyright © 2010 John Wiley & Sons, Ltd.

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