Members Only The Innovative World of Icephobic Coatings
[…] had the pleasure of scraping ice off a car windshield, looking nervously at beautiful but deadly ice spears hanging from winter rooftops, or waiting on a slow and interminably long […]
[…] had the pleasure of scraping ice off a car windshield, looking nervously at beautiful but deadly ice spears hanging from winter rooftops, or waiting on a slow and interminably long […]
[…] For repetitive coatingprocesses, a robot can be a great way to minimize humanexposure, provide a stable and uniform film across monthsand years of production, andnmaximize production through-put. It is not […]
[…] the conflicting requirements for desired properties before and after the coating dries. To maintain a stable dispersion before application, latex particles should be fully dispersible in water, i.e., hydrophilic. However, […]
[…] had the pleasure of scraping ice off a car windshield, looking nervously at beautiful but deadly ice spears hanging from winter rooftops, or waiting on a slow and interminably long aircraft deicing line at an airport has dreamed of having some sort of coating that would eliminate inconvenient ice and snow accumulation. The desire to triumph over ice and snow accumulation has, in fact, been the focus of significant technical work that has been going on since the 1940s in an attempt to make all kinds of surfaces ice and snowphobic. Icephobicity is defined as the ability of a solid surface to repel ice or prevent ice-film formation due to topographical structures at the ice-surface interface. Ice-repelling characteristics are attributed to the surface structure (sometimes called surface roughness) and/or low surface energy leading to poor ice adhesion allowing for easy removal. Icephobic coatings are formulated to ensure that ice doesn’t accumulate on or strongly attach to a surface. In fact, fully functional icephobic coatings operate on several different levels. They can have the ability to repel water droplets, delay ice nucleation, and/or reduce ice adhesion. Icephobic performance is evaluated using two comparative test methods. The ice Centrifuge Adhesion Test (CAT) measures the adhesive failure between the ice and the surface–in other words, the force required to separate the ice buildup from the coating is measured. In this test, a bare aluminum reference and a coated aluminum sample are simultaneously iced by supercooled precipitation. The ice-adhesion shear stress is calculated from the ice-detachment rotation speed. The results are reported as the Adhesion Reduction Factor (ARF), which is the ratio of ice-adhesion stress on the bare aluminum and the ice adhesion stress on the coated sample. The second test method is the Static Ice Accumulation Test (SAT), which measures the amount of ice that accumulates on uncoated reference and coated substrates that are placed at angles of 45° and 80°. The results, reported as the Accumulation Reduction Factor (ACCRF), are the ratio of the ice mass on the bare reference sample over that of the coated sample. Fully functional icephobic coatings operate on several different levels. They can have the ability to repel water droplets, delay ice nucleation, and/or reduce ice adhesion. Over time, a wide range of ARF values, from 0.5 to 1000, have been reported, that correlate to interfacial stresses of 800 kPa and 0.5 kPa respectively.1 Several properties influence icephobicity. Hydrophobicity in particular prevents water droplets from attaching to and penetrating through the surface. Hydrophobicity is a function of water-contact angle. As shown in Figure 1, three levels of hydrophobicity are defined for contact angles >90°. FIGURE 1. Hydrophobicity as defined by liquid contact angle.2 Superhydrophic surfaces (Figure 2) have […]
[…] of transition metals, carbon, and nitrogen. The treasure hunt is finding the ones that are stable. From results of high throughput computing platforms scanning through the formation energies of gazillions […]
[…] Kusumgar, Nerfli & Growney, 2016. For example, see: Landy, F.; Mercurio, A.; Flynn, R., “Shelf stable fast cure aqueous coating,” US Patent 5,527,823. “Standard Test Method for Measurement of Retroreflective […]
[…] expected to dry within a few minutes on the road and yet needs to remain stable in liquid form before being applied. It is a very challenging technical problem to […]
[…] continue to tighten restrictions on coatings containing volatile organic compounds (VOCs), the need for hydrolytically stable additives in waterborne coatings has never been greater. Organofunctional alkoxysilanes are a class of […]
Photolatent additives play a crucial role in the coatings industry. These are thermally stable or latent materials that become reactive after they absorb a photon. Photolatent initiators and catalysts are […]
[…] and viruses. Copper in the +1 oxidation state (Cu+1) is a particularly potent but less stable form of copper, and the innovation in the new additive is that Corning found […]