New method to make glass 'smart' developed

In a major step towards 'smart glass' applications such as 3D display screens or remote radiation sensors, scientists have developed a method for embedding light-emitting nanoparticles into glass without affecting their unique properties.
The new "hybrid glass" successfully combines the properties of these special luminescent (or light-emitting) nanoparticles with the well-known aspects of glass, such as transparency and the ability to be processed into various shapes including very fine optical fibres.
"These novel luminescent nanoparticles, called upconversion nanoparticles, have become promising candidates for a whole variety of ultra-high tech applications such as biological sensing, biomedical imaging and 3D volumetric displays," said Tim Zhao, from the University of Adelaide in Australia.

"Integrating these nanoparticles into glass, which is usually inert, opens up exciting possibilities for new hybrid materials and devices that can take advantage of the properties of nanoparticles in ways we haven't been able to do before," said Zhao.
The method was developed with upconversion nanoparticles, which convert near-infrared radiation into tunable visible light.
However, the researchers, including those from Macquarie University and University of Melbourne, believe their new approach can be generalised to other nanoparticles with interesting photonic, electronic and magnetic properties.

There will be many applications - depending on the properties of the nanoparticle, researchers said.
"If we infuse glass with a nanoparticle that is sensitive to radiation and then draw that hybrid glass into a fibre, we could have a remote sensor suitable for nuclear facilities," said Zhao.

To date, the method used to integrate upconversion nanoparticles into glass has relied on the in-situ growth of the nanoparticles within the glass.
"We've seen remarkable progress in this area but the control over the nanoparticles and the glass compositions has been limited, restricting the development of many proposed applications," said Professor Heike Ebendorff-Heideprem, from University of Adelaide.
"With our new direct doping method, which involves synthesising the nanoparticles and glass separately and then combining them using the right conditions, we've been able to keep the nanoparticles intact and well dispersed throughout the glass," said Ebendorff-Heideprem.
"The nanoparticles remain functional and the glass transparency is still very close to its original quality," she said.

The study was published in the journal Advanced Optical Materials.