Facile preparation of wear-resistant and anti-fingerprint hard coating with chemisorption of fluorosilane by simple wet coating

• Published in: Journal of sol-gel science and technology Vol. 95; no. 2; pp. 447 - 455
• Main Authors: Chansomwong, Kwanchan, Kim, Yun Hyeok, Lee, Hyunhwan, Bae, Byeong-Soo
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2020; Springer Nature B.V
• Subjects: Abrasion resistant coatings; Abrasion resistant steels; Bonding strength; Ceramics; Chemical bonds; Chemisorption; Chemistry and Materials Science; Coefficient of friction; Composites; Contact angle; Fingerprints; Glass; Hard surfacing; Hydrophobicity; Hydroxyl groups; Inorganic Chemistry; Materials Science; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper: Sol-gel and hybrid materials with surface modification for applications; Oxygen plasma; Pretreatment; Primers (coatings); Protective coatings; Silicon dioxide; Siloxanes; Sol-gel processes; Solution heat treatment; Surface chemistry; Wear resistance; Transparent hard coating; Fluorosilane; Abrasion resistance; Anti-fingerprint; Surface treatment; Hydrophobic surface
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-020-05294-z

Epoxy-siloxane hybrid hard coating (HC) has been reported to be applicable to foldable display cover window film due to its glass-like hardness and plastic-like flexibility, which are trade-off characteristics. In addition, to provide an anti-fingerprint (AF) function with abrasion resistance to HC, the addition of a durable hydrophobic function on the HC surface is essential. Herein, durable hydrophobic and abrasion resistant F-HC was reported by chemical adsorption of fluorosilane on HC with simple wet coating. TEOS-derived silica primer increased the hydroxyl groups (–OH) on surface of HC, then it improved the sol-gel condensation with fluorosilane. The fluoro-treatment reduced the coefficient of friction to maintain hydrophobicity (<10% of the initial water contact angle) and optical transparency (~90%) after 5000 cycles of a steel-wool test and 2000 cycles of an eraser abrasion test. Performance was dependent on plasma treatment, annealing condition, and pretreatment on the HC surface for the stronger chemisorption of fluorosilane. Highlights Fluorosilane can be chemically bonded on epoxy-siloxane hybrid hard coating (HC) coating via simple solution treatment without vacuum-based methods. Oxygen plasma, tetraorthosilicate (TEOS)-derived silica primer, and thermal treatments increased the hydroxyl groups on surface of the coating, and alkoxy groups in fluorosilane react with hydroxyl groups by sol-gel condensation. Fluoro-treated hard coating (F-HC) coating maintained excellent optical transparency and hydrophobic surface after steel-wool (5000 cycles) and eraser (2000 cycles) abrasion tests.