[Unconventional Glass2]
Materials design for functional densely packed oxide glasses based on thermophysical properties and atomic arrangements of the melts

RESEARCH OVERVIEW

• Unconventional glasses, a recently discovered class of glass materials, contain little or no or traditional network-former oxides, meaning they do not fit within the framework of conventional glass science.
• The aim of the Materials Design for Functional Densely Packed Oxide Glasses Based on Thermophysical Properties and Atomic Arrangements of the Melts 2 (ELF-Unconventional Glass 2) investigation is to uncover the formation mechanism of unconventional glasses.
• This is achieved by measuring the thermophysical properties of the molten glass, such as density and viscosity, in a microgravity environment then returning solidified samples to Earth for further analysis.
• This research is expected to lead to the establishment of new glass-forming rules for compositions beyond the scope of conventional rules, and it may also bring innovation to the glass industry through the development of new types of glass.

DESCRIPTION

Unconventional glasses are a class of materials that contain little or no traditional network-former oxides, such as silica (SiO2), boron oxide (B2O3), or phosphorus oxide (P2O5). These network-former oxides normally form three-dimensional random networks built from strong corner-sharing tetrahedra, and they act as the backbone of conventional glass structures. A series of oxide glasses that were recently discovered by using levitation techniques are ‘unconventional’ because they do not form corner-sharing tetrahedra but form unusual local structures such as oxygen coordination number greater than four, and edge- or face-sharing polyhedra. The unconventional glasses do not fit within established models of glass science and challenge long-standing theories of glass formation.

The Materials Design for Functional Densely Packed Oxide Glasses Based on Thermophysical Properties and Atomic Arrangements of the Melts 2 (ELF-Unconventional Glass 2) investigation aims to uncover the mechanisms behind how these unconventional glasses form. To achieve this, researchers measure key thermophysical properties of the molten glass, such as density and viscosity, in the unique conditions of microgravity. After solidification, the glass samples are returned to Earth for detailed structural and compositional analysis. These studies aim to provide fundamental insights into atomic arrangements and phase behaviors that cannot be observed using traditional methods. The results are expected to establish new ways to create glass that extend far beyond conventional compositions and may drive innovation in the glass industry through the development of entirely new functional glasses.

SPACE APPLICATIONS

Understanding how unconventional glasses form could open the door to new materials with properties valuable for space exploration. Glasses with higher strength, better resistance to radiation, or improved optical performance could be used in spacecraft windows, habitats, or scientific instruments. In addition, creating new rules for glass formation may enable the design of lightweight, durable materials that can be produced using resources found on the Moon or Mars, supporting long-term human missions beyond Earth.

EARTH APPLICATIONS

Data and samples from this investigation may reveal how to create unconventional glasses with remarkable properties, such as ultra-high refractive indices that surpass diamonds, unbreakable glasses, and glasses that contract instead of expanding when heated. These breakthroughs could transform industries on Earth by advancing technologies in optics, electronics, and materials science.

OPERATIONAL REQUIREMENTS AND PROTOCOLS

A crew member prepares the investigation by inserting the sample holder into the sample cartridge, and inserting the sample cartridge into the Electrostatic Levitation Furnace (ELF) chamber. The ELF is then activated and configured for operation.

To begin investigation operations, a sample is released using the sample release rod. Then, the sample is charged, position controlled, heated, and melted using electrodes and power lasers. During operations, the sample is measured with sensors and recorded by cameras.

At the end of each investigation, the recorded video, pictures, and data (such as temperature and pressure) are downlinked and sent to JAXA’s Tsukuba Space Center.

The investigation operation is completed by deactivating the ELF.

MASUNO Atsunobu [Kyoto University]