title: Surface morphology control of cross-linked polymer particles via dispersion polymerization.
abstract: Cross-linked polymer colloids (poly(methyl methacrylate) and polystyrene) with diverse shapes were prepared in polar solvents (ethanol, methanol and water) via dispersion polymerization, in which a linear addition of the cross-linker was used during reaction. Apart from spherical particles we found dented spheres or particles covered with nodules, or a combination of both. A comprehensive investigation was carried out, mainly concentrating on the effect of the experimental conditions (e.g., the addition start time and total addition time, cross-linker density and the solvency of the solvents) on particle morphologies. Consequently, we suggest a number of effective ways for the synthesis of regular (spherical) colloidal particles through maintaining a relatively low concentration of the cross-linker during the entire reaction, or forcing the co-polymerization (of monomer and cross-linker) locus to the continuous medium, or using a high quality or quantity of the stabilizer. Moreover, the size of the particles was also precisely manipulated by varying the polarity of the solvents, the concentration of the cross-linker, and the amount and average molecular weight of the stabilizer. In addition, the formation of the heavily dented particles with a very rough surface prepared under a pure or oxygen-'contaminated' nitrogen environment was monitored over time. The results accumulated in this article are of use for a better understanding of the mechanism of the polymerization and control over the structure and property of polymer particles.
authors: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands. pengbo006@gmail.com A.Imhof@uu.nl.
authors: Bo
authors: B
authors: Peng
authors: Arnout
authors: A
authors: Imhof
mesh_terms: D003102:Colloids / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D058105:Polymerization; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003102:Colloids; D003432:Cross-Linking Reagents; D011137:Polystyrenes; D012997:Solvents; D019904:Polymethyl Methacrylate; D011205:Povidone