Synthesis of Monodisperse Silica Particles Coated with Well-Defined, High-Density Polymer Brushes by Surface-Initiated Atom Transfer Radical Polymerization

• Published in: Macromolecules Vol. 38; no. 6; pp. 2137 - 2142
• Main Authors: Ohno, Kohji, Morinaga, Takashi, Koh, Kyoungmoo, Tsujii, Yoshinobu, Fukuda, Takeshi
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 22.03.2005
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Monolayer; Surface reaction; Atom transfer polymerization; Methyl methacrylate polymer; Air water interface; Surface topography; Experimental study; Silica; Submicron particle; Monodispersed polymer; Preparation; Microparticle; Monodispersed particle; Graft polymers
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma048011q

Monodisperse silica particles (SiPs) of diameter between 100 and 1500 nm were surface-modified in a mixture of ethanol/water/ammonia with a newly designed triethoxysilane having an atom transfer radical polymerization (ATRP) initiating site, (2-bromo-2-methyl)propionyloxyhexyltriethoxysilane. The surface-initiated ATRP of methyl methacrylate (MMA) mediated by a copper complex was carried out with the initiator-fixed SiPs in the presence of a “sacrificial” (free) initiator. The polymerization proceeded in a living manner in all examined cases, producing SiPs coated with well-defined PMMA of a target molecular weight up to 480K with a graft density as high as 0.65 chains/nm2. These hybrid particles had an exceptionally good dispersibility in organic solvents. Transmission electron microscopic and atomic force microscopic observations of their monolayers prepared at the air−water interface revealed that they formed an ordered 2-dimensional lattice extending throughout the monolayer.