March_2022_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 | M A R C H 2 0 2 2 8 METALS | POLYMERS | CERAMICS emissions. Based on this goal, research- ers from China’s Zhengzhou University and the Chinese Academy of Sciences created a smart material that combines hollow multishelled structure (HoMS) titanium dioxide and a heat-sensitive polymer in order to automatically con- trol heat transmission. The objective of this intelligent material is to perform thermal insulation at relatively low temperatures while dissipating heat when the reaction system overheats. According to the researchers, a hollow structure with multishells can provide more interfaces and thus fur- ther inhibit heat convection and trans- mission, making it more favorable for heat isolation. This new work shows that the thermally responsive poly- mer is a promising model for building thermal fields and reveals, for the first time, the mode of heat transfer through HoMS. This composite exhibits an un- usual two-stage endothermic behavior whereby the direction of heat flow in the material matrix changes. The energy is Heat-treated Al-Mg-Si alloy coatings o er enhanced corrosion resistance to steel. Courtesy of KMOU. PROTECTIVE STEEL COATING The use of aluminum inmarine ap- plications is limited due to its tendency to react with chloride ions in sea water, leading to corrosion. The addition of other elements, such as magnesium and silicon, to forman alloyed coating is a promising way around this problem. But magnesium cannot be easily depos- ited as a coating using the conventional method of dipping the steel into a hot bath of metal salts. Now, scientists at the Korea Maritime and Ocean Univer- sity (KMOU), South Korea, developed a new protocol for aluminum-magne- sium-silicon coating of steel. The researchers took aluminized steel and then plated it withmagnesium using a technique called physical va- por deposition. Next, they exposed the coating to a high temperature of 375°C. They then characterized the coating film and performed corrosion testing in the form of a salt spray test. The scientists found that the corrosion products were formed in two layers—a surface layer made of primarily aluminum-based Vertellus, Indianapolis, acquired Polyscope Polymers B.V., the Netherlands. Polyscope develops and manufactures styrene maleic anhydride copolymers used in applications across the electronic, automotive, and specialty coatings markets. vertellus.com . BRIEF corrosion products, and an inner corrosion layer made of aluminum, magnesium, and silicon-based prod- ucts. Moreover, the inner layer of corrosion prod- ucts produced a shielding effect, which further im- proved their anti-corrosion properties. “Our research reveals how a highly corrosion-re- sistant steel can be produced using a simple change in the surface treatment protocol. This makes it very meaningful for conserving energy and environmen- tal resources,” explains lead researcher Myeong-Hoon Lee. www.kmou.ac.kr/ english/main.do. SMART HEAT ISOLATOR Effective thermal energy manage- ment is a key priority for green produc- tion. As such, developing an intelligent material that can automatically con- trol heat transfer is a way to limit CO 2 Graphical depiction of a multishelled structure embedded with a temperature sensitive polymer, which becomes e ective at thermal accumulation and energy storage.