title: Microcapsule Buckling Triggered by Compression-Induced Interfacial Phase Change.
abstract: There is an emerging trend toward the fabrication of microcapsules at liquid interfaces. In order to control the parameters of such capsules, the interfacial processes governing their formation must be understood. Here, poly(vinyl alcohol) films are assembled at the interface of water-in-oil microfluidic droplets. The polymer is cross-linked using cucurbit[8]uril ternary supramolecular complexes. It is shown that compression-induced phase change causes the onset of buckling in the interfacial film. On evaporative compression, the interfacial film both increases in density and thickens, until it reaches a critical density and a phase change occurs. We show that this increase in density can be simply related to the film Poisson ratio and area compression. This description captures fundamentals of many compressive interfacial phase changes and can also explain the observation of a fixed thickness-to-radius ratio at buckling, [Formula: see text].
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Salmon
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Parker
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Groombridge
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Armando
authors.initials: A
authors.lastname: Maestro
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Coulston
authors.affiliation: Physics Department, TU Dortmund University , Otto-Hahn-Str 4, Dortmund 44221, Germany.
authors.forename: Jonas
authors.initials: J
authors.lastname: Hegemann
authors.affiliation: Physics Department, TU Dortmund University , Otto-Hahn-Str 4, Dortmund 44221, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Kierfeld
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Oren A
authors.initials: OA
authors.lastname: Scherman
authors.affiliation: Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Chris
authors.initials: C
authors.lastname: Abell