title: Transparent coatings made from spray deposited colloidal suspensions.
abstract: The goal of this study is to elaborate few-micrometer thick optically active coatings based on nanoparticles spray-deposited onto a substrate and to control their scattering properties through a progressive suppression of the coffee-ring effect. The modification of the aggregation state of the nanoparticles to be sprayed induces a change of the surface roughness of the films and consequently of their optical transmission. We draw the counterintuitive conclusion that a nonstable colloidal solution gives a smoother coating than a highly stabilized colloidal solution, leading to a more transparent coating. This phenomenon is demonstrated in the case of commercial TiO(2) nanoparticles, as well as of homemade luminescent YVO(4):Eu nanoparticles, and seems to be generalized to a large range of systems.
authors.affiliation: Groupe de Chimie du Solide, Laboratoire de Physique de la Matière Condensée, UMR CNRS 7643, École Polytechnique, 91128 Palaiseau, France.
authors.forename: B
authors.initials: B
authors.lastname: Fleury
authors.forename: G
authors.initials: G
authors.lastname: Dantelle
authors.forename: S
authors.initials: S
authors.lastname: Darbe
authors.forename: J P
authors.initials: JP
authors.lastname: Boilot
authors.forename: T
authors.initials: T
authors.lastname: Gacoin