Print Email Facebook Twitter Tuning roughness and gloss of powder coating paint by encapsulating the coating particles with thin Al2O3 films Title Tuning roughness and gloss of powder coating paint by encapsulating the coating particles with thin Al2O3 films Author Valdesueiro, David (Delft IMP B.V.) Hettinga, Hans (DSM) Drijfhout, Jan Pieter (DSM) Lips, Priscilla (DSM) Meesters, G.M.H. (TU Delft ChemE/Product and Process Engineering) Kreutzer, M.T. (TU Delft ChemE/Chemical Engineering) van Ommen, J.R. (TU Delft ChemE/Product and Process Engineering) Department ChemE/Chemical Engineering Date 2017-08-01 Abstract In this work, we report a method to change the surface finish of a standard polyester-based powder coating paint, from gloss to matt, by depositing ultrathin films of Al2O3 on the powder coating particles. The coating experiments were performed in a fluidized bed reactor at 1 bar and 27 °C, using a gas-phase coating process of alternating exposure of the particles to the two precursors (trimethylaluminium and water), similar to atomic layer deposition (ALD). We varied the number of coating cycles (1, 2, 3, 5, 7 and 9 cycles) to obtain film thicknesses of the alumina shell ranging from 1 to 30 nm. The average growth per cycle of the process is 3.5 nm, significantly larger than the one for pure self-limiting ALD. When the average alumina shell was thicker than 6 nm, the shell prevented the flow of the core particles, even though the powder particles did soften above the glass transition temperature. With the particles morphology intact, this resulted in a rough and matte surface finish of the coating after curing. The surface roughness, with a value around 9 μm determined by surface profilometry, is associated to the alumina coated particles as observed with SEM and EDX analysis. In addition, the matte finish coating showed mechanical resistance similar to that of uncoated powder particles. Subject Alumina coatingAmbient conditionsAtomic layer depositionCore-shell particlesMatte powder coatingSurface appearance To reference this document use: http://resolver.tudelft.nl/uuid:77ed6a3b-a5c9-4f0c-83cb-d3f0e3082a36 DOI https://doi.org/10.1016/j.powtec.2017.05.019 ISSN 0032-5910 Source Powder Technology, 318, 401-410 Part of collection Institutional Repository Document type journal article Rights © 2017 David Valdesueiro, Hans Hettinga, Jan Pieter Drijfhout, Priscilla Lips, G.M.H. Meesters, M.T. Kreutzer, J.R. van Ommen Files PDF 1_s2.0_S0032591017303947_main.pdf 2.54 MB Close viewer /islandora/object/uuid:77ed6a3b-a5c9-4f0c-83cb-d3f0e3082a36/datastream/OBJ/view