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A D V A N C E D M A T E R I A L S & P R O C E S S E S | A P R I L 2 0 2 0 9 SURFACE ENGINEERING ANTI-ICE HYDROGEL ACTS IN THREE DISTINCT WAYS International scientists from Chi- na and the University of California, Los Angeles (UCLA), have developed a new coating that prevents ice formation on critical equipment. Inspired by a natu- ral mechanism that keeps blood from freezing in several species of Antarcti- ca-based fish, the scientists say their coating could be a versatile and inex- pensive anti-ice solution for critical parts on outdoor pipes, airplane wings, and other equipment. The researchers say the material is simple to make and very durable. The gel is made mostly of water, but its key ingredient is polydimethylsiloxane, a nontoxic, silicone-based polymer used in products such as contact lenses, cos- metics, and lubricants. When sprayed onto a surface, it forms a thin, transparent coat that helps prevent freezing in three differ- ent ways—lowering the freezing temperature of water on the sur- face, delaying ice crystals from growing, and making the surface difficult for ice to adhere. The researchers tested the coating on several mate- rials, including plastic, glass, ceramics, and metals. It set a record by preventing ice from forming until the temperature reached − 31°C. Even if ice suc- ceeds in forming on an object’s surface, the hydrogel coating makes it easy to remove the ice by simply brushing or blowing it off, without scraping the object or apply- ing heat. In the 1960s, scientists discov- ered that several species of Antarctic fish make proteins that work as an an- tifreeze for their bloodstreams. The new coating works in part through mimicking the molecular structure of those proteins. The new UCLA material is the first of its kind that prevents ice formation by acting on the three distinct aspects of the natural process. ucla.edu . CREATING METALS WITH BUOYANCY A team of University of Rochester, N.Y., researchers has developed a new tech- nique to introduce hydrophobic prop- erties tometal withpotentially industry- changing results. The team uses lasers to etch tiny grooves into the surface of an alu- minum disk. These grooves trap air bubbles against the metal, forming a hydrophobic barrier to water passing through. Because the process is applied to the material itself, the water-repel- ling effect is permanent without the need for reapplication. Researchers tested damage resis- tance by drilling holes into disks and dropping them into water. No matter how many holes they drilled, the disks continued to float. The metal also be- comes self-cleaning—a few drops of water were enough to remove any dust and dirt placed on the array. According to the team, the array’s innate buoyancy anddamage resistance mean ships and vessels constructed out of this material would take a great step toward being legitimately “unsinkable.” The greatest challenge to the widespread use of this array is that it’s time-consuming to create, taking an hour to pattern a 1x1" sample. Current- ly, research is being directed toward re- ducing production time. rochester.edu. BRIEF Paint and coatings giant PPG, Pittsburgh, has acquired Illinois powder coatings manufacturer Alpha Coating Technologies, West Chicago. Alpha develops, produces, and sells powder coatings for light industrial applications, medium- density fiberboard, and heat-sensitive substrates. It also manufactures coatings for outside companies in metal production and light industry. ppg.com . A new coating could be an inexpensive solution for preventing airplane wing components and other outdoor equipment from freezing in cold temperatures. Courtesy of Wikipedia Commons/ Cory W. Watts. Possible applications for the buoyant metals include the construction of ships and vessels, as well as rainwater collectors. Courtesy of the Navy/ Jonathan Ste en.