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Published on: October 11, 2016
Relation between surface roughness of free films and process parameters in spray coating
G Perfetti1, T Alphazan, P van Hee
1Nanostructured Materials Group, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 136, NL-2628 BL Delft, The Netherlands. g.perfetti@tudelft.nl
Summary
A new spray apparatus creates reproducible free films with adjustable roughness. This technology mimics particle coating morphology, offering tuneable surface properties for advanced material applications.
Area of Science:
- Materials Science
- Chemical Engineering
- Surface Science
Background:
- Reproducible free films are crucial for material science applications.
- Existing methods for creating free films often lack control over surface properties.
- Developing novel apparatus for controlled film formation is essential.
Purpose of the Study:
- To develop and characterize a novel spraying apparatus for producing reproducible free sprayed films.
- To achieve tuneable surface roughness and morphology in free films.
- To compare the morphology of sprayed films with reference coated particles.
Main Methods:
- Utilized a spraying apparatus with a computerized control system, pressurized air, and a rotating cylinder.
- Employed aqueous solutions of PolyVinyl Alcohol (PVA) and HydroxyPropyl MethylCellulose (HPMC) as coating materials.
- Optimized spraying parameters (air pressure, rotation speed, nozzle distance) using design of experiments.
- Evaluated film morphology using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM).
Main Results:
- The novel apparatus successfully produced reproducible free sprayed films.
- Optimized conditions yielded films with roughness comparable to reference coated particles.
- SEM and AFM analysis confirmed that the morphology of sprayed films matched the coating layer on particles.
- The apparatus allows for tuneable roughness and smoothness by adjusting processing parameters.
Conclusions:
- The developed spray apparatus provides a reliable method for generating free films with controlled surface characteristics.
- The film morphology closely replicates that of coatings on particle surfaces.
- This technology offers potential for creating advanced materials with tailored surface properties.
