Wetting Characteristics of Nanosilica-Poly (acrylic acid) Transparent Anti-Fog Coatings

• Published in: Polymers Vol. 14; no. 21; p. 4663
• Main Authors: Turkoglu, Sevil, Zhang, Jinde, Dodiuk, Hanna, Kenig, Samuel, Ratto, Jo Ann, Mead, Joey
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.11.2022; MDPI
• Subjects: Acids; Acrylic acid; anti-fogging; Atomic force microscopy; Coating effects; Coatings; Contact angle; Fog; Fogging; Functional groups; Glass substrates; Humidity; Hydrophilic surfaces; Hydrophilicity; Hydrophobic surfaces; Light; Microscopy; nanocomposite coating; Nanocomposites; Nanoparticles; Polyacrylic acid; Silica; Substrates; superhydrophilicity; Surface chemistry; surface wetting; Topography; Wettability; Wetting; United States > US; nanocomposite coating; surface wetting; superhydrophilicity; anti-fogging
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym14214663

The effect of particle loading on the wetting properties of coatings was investigated by modifying a coating formulation based on hydrophilic silica nanoparticles and poly (acrylic acid) (PAA). Water contact angle (WCA) measurements were conducted for all coatings to characterize the surface wetting properties. Wettability was improved with an increase in particle loading. The resulting coatings showed superhydrophilic (SH) behavior when the particle loading was above 53 vol. %. No new peaks were detected by attenuated total reflection (ATR-FTIR). The surface topography of the coatings was studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The presence of hydrophilic functional groups and nano-scale roughness were found to be responsible for superhydrophilic behavior. The surface chemistry was found to be a primary factor determining the wetting properties of the coatings. Adhesion of the coatings to the substrate was tested by tape test and found to be durable. The antifogging properties of the coatings were evaluated by exposing the films under different environmental conditions. The SH coatings showed anti-fogging behavior. The transparency of the coatings was significantly improved with the increase in particle loading. The coatings showed good transparency (>85% transmission) when the particle loading was above 84 vol. %.