Microencapsulation of an acrylate monomer in silica particles by sol–gel process

• Published in: Journal of sol-gel science and technology 2011-02, Vol.57 (2), p.164-171
• Main Authors: Nistor, Cristina Lavinia, Donescu, Dan, Perichaud, Alain, Ballout, Wael, Ghiurea, Marius
• Format: Article
• Language: English
• Subjects: Ammonium hydroxide; Catalysis; Ceramics; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Emulsions. Microemulsions. Foams; Encapsulation; Ethers; Ethylene glycol; Exact sciences and technology; General and physical chemistry; Glass; Hardeners; Inks; Inorganic Chemistry; Materials Science; Microencapsulation; Monomers; Morphology; MPEG encoders; Nanotechnology; Natural Materials; Networks; Optical and Electronic Materials; Original Paper; Precursors; Silica gel; Silicon dioxide; Sol gel process; Sol-gel processes; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Thermal analysis; Video compression
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-010-2337-z

The sol–gel synthesis strategies combined with the templated growth of organic–inorganic hybrid networks provide access to an immense new area of innovative multi-functional advanced materials. One possible way to prepare such new advanced materials is to encapsulate liquid active agents (such as monomers, dyes, catalysts and hardeners) in microcapsules. Silica microcapsules of tetraethylortosilicate (TEOS) and 3-(trimethoxysilyl)propyl methacrylate (MPTS) were prepared in a precursor-monomer/NH 4 OH water microemulsion system. Trimethylolpropane triacrylate (TMPTA)—a trifunctional monomer useful in manufacturing of coatings, inks and adhesives—and a corresponding photoinitiator (DAROCUR 1173) were entrapped inside the obtained microcapsules. MPTS was used to increase compatibility between TMPTA and the sol–gel precursors. As stability agent we added a “home made” product resulted from functionalization of poly (ethylene glycol) methyl ether (MPEG) with (3-isocyanatopropyl) triethoxysilane (NCOTEOS). Were obtained microcapsules containing incorporated monomer and having average particle size in range of 0.5–50 μm. Thermal analysis, morphology study and the increase of the silica microcapsules average diameter, measured by DLS technique confirm the monomer encapsulation.