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 2 1 1 is easy to synthesize, also has high durability and multiple applications. The research group has been investigating and developing the properties of hackmanite for almost a decade. Applications such as personal UV monitoring and x-ray imaging have been developed based on hackmanite’s ability to change color. Hackmanite changes its color from white to purple under UV irradiation, eventually turning back to white if no UV is present. Until now, the structural features enabling repeated changes have been poorly understood. Through their work investigating three natural minerals—hackmanite, tugtupite, and scapolite—the researchers are gaining a clearer picture. These color-changing minerals are inorganic natural materials, but there are also organic compounds— hydrocarbons—that can change color reversibly due to radiation exposure. However, these hydrocarbons can only change color a few times before their Hackmanite turns purple under UV irradiation, and color fades back to white in minutes under regular white light. Courtesy of Mika Lastusaari. molecular structure breaks down. This is because the color change involves a drastic change in their structure, and undergoing this change repeatedly eventually breaks the molecule. Previously, scapolite has been known to change color much faster than hackmanite, whereas tugtupite’s changes are much slower. According to researchers, the durability of the inorganic natural materials under investigation is due to the strong 3D cage-like overall structure of these minerals, which is similar to that of zeolites. In detergents, for example, the cage-like structure enables zeolite to remove magnesium and calcium fromwater by binding them tightly inside the pores of the cage. The group is currently exploring numerous applications for hackmanite, such as replacing LEDs and other light bulbs with the natural mineral as well as utilizing it in x-ray imaging. One of the most interesting avenues that the researchers are also investigating is a hackmanite-based dosimeter and passive detectors for the International Space Station, intended to be used to measure the radiation dose uptake of materials during space flights. www. utu.fi/en.
RkJQdWJsaXNoZXIy MTYyMzk3NQ==