Title New strategies to create technologically relevant superomniphobic coatings on sol-gel base
Date 01.08.2017
Number 52205
Abstract Omniphobic and superomniphobic sol-gel coatings have been prepared on technical scale by sol-gel formulations modified with a perfluoropolyether and/or a fluoropolymer nanoparticle dispersion. Single and two-layer coatings were prepared by spraying or coating with a doctor blade. They exhibited a broad range of different morphologies leading to different wetting behavior. Under certain preparation conditions (spraying at elevated temperature, high surface coverage), the single-layer coatings with perfluoropolyether and fluoropolymer nanoparticles exhibited a hierarchical structuring at various length scales, high roughness and aspect ratio, re-entrant structures and superomniphobic behavior. The mechanical stability of these layers was sufficient to maintain superhydrophobicity and oleophobicity after a harsh wet abrasion test. Two-layer coatings with a smooth low-energy top coat on a rough fluorine-free base coat had a higher mechanical stability but showed an insatisfactory wetting behavior. Systematic investigation of the correlations between roughness, liquid surface tension and advancing/receding contact angle of water, water-ethanol mixtures and hexadecane confirmed the existing theories. The self-cleaning properties of the rough coatings were good for polar soils; for oils they are very sensitive to layer defects.
Publisher Progress in Organic Coatings
Identifier 0
Citation Progress in Organic Coatings 109 (2017) 160-171
Authors Drechsler, A. ; Estel, K. ; Caspari, A. ; Bellmann, C. ; Harenburg, J. ; Meier, F. ; Zschuppe, M.
Tags superomniphobic self-cleaning sol-gel wetting mechanical stability

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