title: Photoactive, porous honeycomb films prepared from Rose Bengal-grafted polystyrene.
abstract: Honeycomb-structured porous polymer films based on photosensitizer-grafted polystyrene are prepared through the breath figure process. Rose Bengal (RB) photosensitizer is first attached to a well-defined poly(styrene-stat-4-vinylbenzyl chloride) statistical copolymer, synthesized by nitroxide-mediated radical polymerization. The RB grafted poly(styrene-stat-4-vinylbenzyl chloride) (ca. 20,000 g mol(-1) molar mass, 1.2 dispersity) leads to porous polymer films, with a hexagonal pore pattern, while a simple mixture of poly(styrene-stat-4-vinylbenzyl chloride) and the insoluble RB photosensitizer produced unstructured, nonporous films. The RB-grafted honeycomb films, compared with the corresponding nonporous flat films, are more efficient for oxidation of organic molecules via singlet oxygen production at a liquid/solid interface. The oxidations of 1,5-dihydroxynaphthalene to juglone and α-terpinene to ascaridole are followed in ethanol in the presence of both types of films. Oxidation of the organic molecules is a factor 5 greater with honeycomb compared to the nonporous films. This gain is ascribed to two factors: the specific location of the polar photosensitizer at the film interface and the greater exchange surface, as revealed by fluorescence and scanning electron microscopies.
authors.affiliation: CNRS, University of Pau and Pays de l'Adour, UMR 5254, IPREM, Equipe de Physique et Chimie des Polymères, 2 avenue du Président Angot, Pau, F-64053, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Pessoni
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lacombe
authors.forename: Laurent
authors.initials: L
authors.lastname: Billon
authors.forename: Ross
authors.initials: R
authors.lastname: Brown
authors.forename: Maud
authors.initials: M
authors.lastname: Save
mesh_terms: D015394:Molecular Structure; D010316:Particle Size; D055668:Photochemical Processes; D017319:Photosensitizing Agents / Q000737:chemistry*; D011137:Polystyrenes / Q000138:chemical synthesis / Q000737:chemistry*; D016062:Porosity; D012395:Rose Bengal / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D017319:Photosensitizing Agents; D011137:Polystyrenes; D012395:Rose Bengal