Conversion of Colloidal Crystals to Polymer Nets:  Turning Latex Particles Inside Out

Abstract

Copolymer latexes of styrene and 5-10 mol % 2-hydroxyethyl methacrylate (HEMA) with narrow polydispersity produce films of colloidal crystals on glass by evaporative deposition. Treatment with vapors of styrene or toluene followed by drying transforms the morphology of the film to a porous polymer net with hexagonally ordered holes on the surface. We propose that the conversion takes place by swelling of styrene into the polystyrene-rich cores of the particles, which expand and engulf the polyHEMA-rich shells, leaving the polystyrene-rich phase on the surface and the polyHEMA-rich phase inside after the styrene evaporates. Evidence for the polyHEMA-rich surface of the colloidal crystal and the polystyrene-rich surface of the net is provided by contact angle measurements that show the surface of the net to be more hydrophobic than the colloidal crystal and by X-ray photoelectron spectroscopic measurements that show a higher oxygen content on the surface of the colloidal crystal than on the surface of the net.

Preparation and characterization of conductive carbon nanotube–polystyrene nanocomposites using latex technology

“…The ability to assemble these colloidal particles into crystalline arrays allows one to obtain useful and remarkable functionalities not only from the fundamental physics of systems with the long-range, mesoscopic order that characterizes periodic structures but also from the application of constituent materials [1][2][3][4]. All these applications are strongly dependent on the availability of colloidal spheres with tightly controlled sizes and high monodispersity (<5%).…”

3D Ordered Macroporous Materials

“…Another method employing core-shell structures as precursors for macroporous materials is core-shell rearrangement [140,141]. In this method, colloidal crystals composed of latex spheres with PS-rich cores and poly(2-hydroxyethyl methacrylate)-rich shells (i.e.…”

A Facile One‐Step Method to Prepare Three‐Dimensional Ordered Latex Particles

“…Colloidal spheres can also pack tightly into fcc crystals in which the spheres occupy 74% of the volume. [6] Colloidal crystals are similar to molecular crystals, but the building blocks are colloidal particles instead of molecules. Colloidal crystals are formed mainly with an electrostatic interparticle repulsion and an expanded electrical double layer around the spheres in the deionized state.…”