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

Abstract

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. %.

Multifunctional Amphiphobic Coating toward Ultralow Interfacial Adhesion of Hydrates

“…A concentrated TBAB solution has a strong corrosion effect on Cu and other metals. , The stability of the Cu substrate with a PF/ZSM-5 coating was tested in a TBAB solution (30 wt %). As shown in Figure c, the water contact angle of the PF/ZSM-5 coating decreased from 162° to 154° after soaking for 300 d. However, it was still greater than 150°, meeting the requirement of superhydrophobicity, that is, the water contact angle is larger than 150° and the water sliding angle is smaller than 10°. − The sliding angle increased from 2° to 17°, which indicated that the PF/ZSM-5 surface transformed from a Cassie wet state to a semi-Cassie/Wenzel wet state after prolonged immersion. Figure d shows photographs of the surface morphology of the samples after soaking in TBAB solution for 300 d. The surface of the Cu plate was seriously damaged due to the generation of corrosion products, while brown corrosion products were observed on the GF-2200 surface .…”

Hydrophilic and Hydrophobic Surfaces: Features of Interaction with Liquid Drops

“…The dynamic inflow and outflow wetting angles on such surfaces were 30 • and 0 • , respectively. When thin films of silica nanoparticles and poly(acrylic acid) were deposited on glass, it was determined that the chemical composition of the surface is the main factor determining the wetting properties of the coatings [24]. It was established that with an increase in the volume concentration of silicon in the solution during coating on glass, the contact angle of wetting with water decreases.…”

“…has increased manifold over the past 5-7 years due to the active development of measuring technologies [22,23]. In studies of the interaction between drops and surfaces, materials are used that are characterized by different textures: glass [24], silicon [25], aluminum [15], copper [26], steel [27], etc. The properties of the liquid and the surface are strong influences on the mode and consequences of interaction.…”

Superhydrophobicity Mechanism and Nanoscale Profiling of PDMS-Modified Kaolinite Nanolayers via Ab Initio-MD Simulation and Atomic Force Microscopy Study

“…The angle, denoted as θ, is the included angle between the gas–liquid interface and the solid–liquid interface. Surfaces with θ values below 10° and between 10 and 90° are defined as superhydrophilic and hydrophilic surfaces, , respectively, while those with θ values higher than 90° are hydrophobic. Surfaces with θ values exceeding 150° and a sliding angle less than 10° are designated as superhydrophobic .…”