title: Monitoring the transformation of colloidal crystals by styrene vapor using atomic force microscopy.
abstract: The stages of transformation of a colloidal crystalline film of latex spheres to a new periodic structure were imaged by atomic force microscopy. Colloidal crystalline films were prepared with 320 nm diameter poly(styrene-co-2-hydroxyethyl methacrylate) (PSt/HEMA) spheres. The hexagonally ordered surfaces of the colloidal crystalline films were transformed with styrene vapor at room temperature to a new morphology having holes in the surface and the same periodicity as the original films. The surfaces of colloidal crystals and the transformed films have a raspberry-like texture superposed on the 320 nm hexagonal periodicity. Both height images and phase images reveal that the latex spheres shrink and the transformation proceeds by an order-disorder-order sequence. The final structure is an interconnected colloidal array with smaller polystyrene particles dispersed in a continuous PSt/HEMA matrix.
authors.affiliation: Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
authors.forename: Dongqi
authors.initials: D
authors.lastname: Qin
authors.forename: Susheng
authors.initials: S
authors.lastname: Tan
authors.forename: Shuhui
authors.initials: S
authors.lastname: Qin
authors.forename: Warren T
authors.initials: WT
authors.lastname: Ford