title: Autostratification in drying colloidal dispersions: experimental investigations.
abstract: In films cast from a colloidal dispersion comprising two particle sizes, we experimentally examine the distribution of particles normal to the substrate. The particle concentrations at various positions in the film are determined through atomic force microscopy and NMR profiling. The results are compared to a previously derived diffusional model. Evidence for diffusional driven stratification is found, but the importance of other flows is also highlighted. The conditions that enhance particle stratification are found to be a colloidally stable dispersion, low initial volume fractions, a low concentration of the stratifying particle, and for the Peclet numbers of the two components to straddle unity.
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, United Kingdom.
authors.forename: R E
authors.initials: RE
authors.lastname: Trueman
authors.forename: E
authors.initials: E
authors.lastname: Lago Domingues
authors.forename: S N
authors.initials: SN
authors.lastname: Emmett
authors.forename: M W
authors.initials: MW
authors.lastname: Murray
authors.forename: J L
authors.initials: JL
authors.lastname: Keddie
authors.forename: A F
authors.initials: AF
authors.lastname: Routh