GUANGZHOU, China, Jan. 28, 2016 — A novel fabrication method has produced glass that protects living cells and organic dyes from UV damage, and could be used to shield electronics in space from the detrimental effects of UV radiation.
Researchers from South China University of Technology used cerium (IV) oxide, or CeO2, to craft the composite glass-based UV absorber using a method involving the self-limited nanocrystallization of glass.
The optically transparent composite material demonstrated the ability to suppress the separation of photogenerated electrons and holes, the researchers said, which slowed down the light-induced reaction that would lead to breakdown of the material under prolonged exposure to UV radiation.
These images show UV-induced morphological changes of multinucleated giant cells, unprotected and protected by the group's UV absorber. Courtesy of Shifeng Zhou/South China University of Technology.
The team said its fabrication technique enabled functionalization of the glass material: It suppressed photocatalytic and catalytic activity, while boasting high UV-absorbing capacity.
"Self-limited nanocrystallization of glass can be achieved by taking advantage of the rigid environment of the solid-state matrix, rather than the conventional solution and vapor conditions to modulate the ionic migration kinetics," said professor Shifeng Zhou. "It allows us to create glass-ceramics embedded with a CeO2:fluorine (F) nanostructure."
The viscous glass matrix involved posed a constraint for O2- and F- ion diffusion, so the group etched trifluorocerium (CeF3) by O2 ions within an oxide matrix until F-doped CeO2 was generated. The researchers said this technique is routinely used to prepare other UV absorbers, such as zinc oxide and titanium oxide.
Potential applications for the technology include radiation hardening of electronic devices, serving as a biological shield, and preserving cultural artifacts and relics.
"In space, the high-energy radiation environment encountered by electronic equipment aboard spacecraft can be quite damaging," Zhou said. "Fortunately, in the future, if you add a radiation-blocking coating onto the surface of the package — a transparent glass/polymer material — the device would be well protected, and its service lifetime may be prolonged."
The researcher said they will focus future efforts on developing other novel and effective glass-based UV absorbers, using the self-limited nanocrystallization method, as well as large-scale fabrication methods to enable practical application.
The research was published in Optical Materials Express, a publication of The Optical Society (OSA) (doi: 10.1364/ome.6.000531).