title: Time-resolved small-angle X-ray scattering studies of polymer-silica nanocomposite particles: initial formation and subsequent silica redistribution.
abstract: Small angle X-ray scattering (SAXS) is a powerful characterization technique for the analysis of polymer-silica nanocomposite particles due to their relatively narrow particle size distributions and high electron density contrast between the polymer core and the silica shell. Time-resolved SAXS is used to follow the kinetics of both nanocomposite particle formation (via silica nanoparticle adsorption onto sterically stabilized poly(2-vinylpyridine) (P2VP) latex in dilute aqueous solution) and also the spontaneous redistribution of silica that occurs when such P2VP-silica nanocomposite particles are challenged by the addition of sterically stabilized P2VP latex. Silica adsorption is complete within a few seconds at 20 °C and the rate of adsorption strongly dependent on the extent of silica surface coverage. Similar very short time scales for silica redistribution are consistent with facile silica exchange occurring as a result of rapid interparticle collisions due to Brownian motion; this interpretation is consistent with a zeroth-order Smoluchowski-type calculation.
authors.affiliation: Dainton Building, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, UK.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Balmer
authors.forename: Oleksandr O
authors.initials: OO
authors.lastname: Mykhaylyk
authors.forename: Steven P
authors.initials: SP
authors.lastname: Armes
authors.forename: J Patrick A
authors.initials: JP
authors.lastname: Fairclough
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Ryan
authors.forename: Jeremie
authors.initials: J
authors.lastname: Gummel
authors.forename: Martin W
authors.initials: MW
authors.lastname: Murray
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Murray
authors.forename: Neal S J
authors.initials: NS
authors.lastname: Williams