Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/65368
Type: Artigo de periódico
Title: Efficient Preparation of Polystyrene/Silica Colloidal Nanocomposite Particles by Emulsion Polymerization Using a Glycerol-Functionalized Silica Sol
Author: Schmid, A
Armes, SP
Leite, CAP
Galembeck, F
Abstract: Colloidally stable polystyrene/silica nanocomposite particles of around 200-400 nm diameter and containing 22-28 wt % silica can be readily prepared by aqueous emulsion polymerization at 60 degrees C using a cationic azo initiator in combination with a commercially available glycerol-functionalized ultrafine aqueous silica sol in the absence of any surfactant, auxiliary comonomer, or nonaqueous cosolvent. Optimization of the initial silica sol concentration allows relatively high silica aggregation efficiencies (up to 95%) to be achieved. Control experiments confirm the importance of selecting a cationic initiator, since nanocomposite particles were not formed when using an anionic persulfate initiator. Similarly, the glycerol groups on the silica sol surface were also shown to be essential for successful nanocomposite particle formation: use of an unfunctionalized ultrafine silica sol in control experiments invariably led to polystyrene latex coexisting with the silica nanoparticles, rather than efficient nanocomposite formation. Electron spectroscopy imaging transmission electron microscopy studies of ultramicrotomed polystyrene/silica nanocomposite particles indicate well-defined "core-shell" particle morphologies, which is consistent with both X-ray photoelectron spectroscopy and aqueous electrophoresis studies.
Country: EUA
Editor: Amer Chemical Soc
Rights: fechado
Identifier DOI: 10.1021/la803544w
Date Issue: 2009
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File Description SizeFormat 
WOS000263373600086.pdf385.16 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.