September_AMP_Digital

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 | S E P T E M B E R 2 0 2 0 1 4 SURFACE ENGINEERING POLYMER COATING PREVENTS FUNGI All over the world, fungi cause di- verse and significant socioeconomic problems—globally, $30 billion is spent each year in the fungicide industry. Now, scientists from the U.K.’s Universi- ty of Nottingham developed a new way to control harmful fungi without using chemical bioactives such as antifun- gals. The innovative solution passively blocks fungal attachment to surfaces using a coating of methacrylate poly- mers, eliminating the need to use po- tentially harmful chemicals. Through previous work, the team found different combinations of fun- gicides that worked against fungi and produced new understanding of pre- servative action against spoilage fungi. Potential bioactive-free technologies for combatting fungi are increasingly attractive to the industry as regulations and restrictions continue to tighten and public resistance grows against chemi- cally based strategies. For their alternative fungal con- trol method, the scientists identified polymers that resist the attachment of different kinds of fungi, including pathogens. Specific chemical features of the methacrylate polymers such as their nontoxic nature were associated with weak fungal attachment. A similar approach against bacterial pathogens is also being developed for a catheter coating to prevent infections in pa- tients. The scientists say their work is the first high-throughput study of poly- mer chemistries resisting fungal attach- ment. www.nottingham.ac.uk . ARMOR-PLATED MATERIAL REPELS WATER A collaboration between research- ers in Finland and China produced an armor-plated superhydrophobic sur- face that can take repeated damage from sharp and blunt objects while repelling liquids with world-record ef- fectiveness. The team designed super- hydrophobic surfaces that can be made of metal, glass, or ceramic. Nanosized structures covering the surfaces—in a honeycomb-like pattern with tiny in- verted pyramids—enable the superhy- drophobic properties after a fragile wa- ter-repellent chemical is coated within the tiny structures. This prevents any liquid from sticking to the surface, and the fragile chemical coating is protected from damage by the pyramids’ walls. “The armor can be made from al- most any material,” the scientists say. “It’s the interconnection of the surface frame that makes it strong and rigid.” As well as their useful antimicrobi- al properties for biomedical technolo- gy, superhydrophobic surfaces can also be used more generally in any applica- tion requiring a liquid-repellent surface. One example is photovoltaics, where the buildup of moisture and dirt over time blocks the amount of light they can absorb, which reduces electricity pro- duction. Making a solar panel out of a superhydrophobic glass surface would maintain their efficiencies over long pe- riods of time. Further, as solar cells are often on roof tops and other difficult to reach locations, the repellent coatings would cut down the amount of cleaning that is needed. Other desirable applications for superhydrophobic surfaces include ma- chines and vehicles, where conditions can be very tough for brittle materials for long periods of time. To simulate these working environments, the re- searchers subjected their new surfaces to extreme conditions, including baking them at 100°C nonstop for weeks, im- mersing them in highly corrosive liquids for hours, blasting themwith high-pres- sure water jets, and subjecting them to physical exertion in extreme humidity. The surfaces were still able to repel liq- uid as effectively as before. www.aalto. fi/en, en.uestc.edu.cn . BRIEF Curtiss-Wright’s Surface Technologies Division, Paramus, N.J., reports that its Microseal impingement lubricant coating process has been utilized on numerous components on NASA’s Mars 2020 mission, many within the sample caching system on the Perseverance Rover. This mission will seek signs of past microbial life and collect rock and soil samples for potential return to Earth. cwst.com . Candida albicans. A depiction of how a superhydrophobic material repels water. Courtesy of Aalto University. Perseverance Rover. Courtesy of NASA.gov.