title: Colloidal suspensions of functionalized mesoporous silica nanoparticles.
abstract: The synthesis and characterization of colloidal mesoporous silica (CMS) functionalized with vinyl-, benzyl-, phenyl-, cyano-, mercapto-, aminopropyl- or dihydroimidazole moieties is reported. Uniform mesoporous particles ranging in size from 40 to 150 nm are generated in a co-condensation process of tetraethylorthosilicate (TEOS) and organotriethoxysilanes (RTES) in alkaline aqueous media containing triethanolamine (TEA) in combination with cetyltrimethylammonium chloride (CTACl) serving as a structure-directing agent. The materials are obtained as colloidal suspensions featuring long-term stability after template removal by ion exchange with an ethanolic solution of ammonium nitrate or HCl. The spherical particles exhibit a wormlike pore system with defined pore sizes and high surface areas. Samples are analyzed by a number of techniques including TEM, SEM, DLS, TGA, Raman, and cross-polarized (29)Si-MAS NMR spectroscopy, as well as nitrogen sorption measurements. We demonstrate that co-condensation and grafting methods result in similar changes in the nitrogen adsorption behavior, indicating a successful internal lining of the pores with functional groups through both procedures.
authors.affiliation: Department of Chemistry and Biochemistry and Center for NanoScience (CeNS), University of Munich, Butenandtstrasse 5-13 (E), D-81377 Munich, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Kobler
authors.forename: Karin
authors.initials: K
authors.lastname: Möller
authors.forename: Thomas
authors.initials: T
authors.lastname: Bein
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D003102:Colloids; D046911:Macromolecular Substances; D012822:Silicon Dioxide