Fielding, L.A., Tonnar, J. and Armes, S.P. (2011) All-acrylic film-forming colloidal polymer/silica nanocomposite particles prepared by aqueous emulsion polymerization. Langmuir, 27 (17). 11129 - 11144. ISSN 0743-7463
Abstract
The efficient synthesis of all-acrylic, film-forming, core–shell colloidal nanocomposite particles via in situ aqueous emulsion copolymerization of methyl methacrylate with n-butyl acrylate in the presence of a glycerol-functionalized ultrafine silica sol using a cationic azo initiator at 60 °C is reported. It is shown that relatively monodisperse nanocomposite particles can be produced with typical mean weight-average diameters of 140–330 nm and silica contents of up to 39 wt %. The importance of surface functionalization of the silica sol is highlighted, and it is demonstrated that systematic variation of parameters such as the initial silica sol concentration and initiator concentration affect both the mean particle diameter and the silica aggregation efficiency. The nanocomposite morphology comprises a copolymer core and a particulate silica shell, as determined by aqueous electrophoresis, X-ray photoelectron spectroscopy, and electron microscopy. Moreover, it is shown that films cast from n-butyl acrylate-rich copolymer/silica nanocomposite dispersions are significantly more transparent than those prepared from the poly(styrene-co-n-butyl acrylate)/silica nanocomposite particles reported previously. In the case of the aqueous emulsion homopolymerization of methyl methacrylate in the presence of ultrafine silica, a particle formation mechanism is proposed to account for the various experimental observations made when periodically sampling such nanocomposite syntheses at intermediate comonomer conversions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2011 ACS. This is an author produced version of a paper subsequently published in Langmuir. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Polystyrene Composite-Particles; Cationic AZO Initiator; Alcoholic Dispersion Polymerization; Ray Photoelectron-Spectroscopy; Sterically-Stabilized Latexes; Miniemulsion Polymerization; Silica Nanoparticles; Surface Characterization; Radical Polymerization; Inorganic Particles |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Chemistry (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 10 Jun 2014 12:08 |
Last Modified: | 04 Nov 2017 14:02 |
Published Version: | http://dx.doi.org/10.1021/la202066n |
Status: | Published |
Publisher: | American Chemical Society |
Refereed: | No |
Identification Number: | 10.1021/la202066n |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:79025 |