Vitrification - Applications

Applications

Ordinary soda-lime glass, used in windows and drinking containers, is created by the addition of sodium carbonate and lime (calcium oxide) to silicon dioxide. Without these additives silicon dioxide will require very high temperature to obtain a melt and subsequently (with slow cooling) a glass.

Vitrification is a proven technique in the disposal and long-term storage of nuclear waste or other hazardous wastes. Waste is mixed with glass-forming chemicals in a melter to form molten glass that then solidifies in canisters, immobilizing the waste. The final waste form resembles obsidian and is a non-leaching, durable material that effectively traps the waste inside. The waste can be stored for relatively long periods in this form without concern for air or groundwater contamination. Bulk vitrification uses electrodes to melt soil and wastes where they lay buried. The hardened waste may then be disinterred with less danger of widespread contamination. According to the Pacific Northwest National Labs, "Vitrification locks dangerous materials into a stable glass form that will last for thousands of years."

Ethylene glycol is used as automotive antifreeze and propylene glycol has been used to reduce ice crystals in ice cream, making it smoother.

Vitrification in cryopreservation is used as a common method to preserve, for example, human egg cells (oocytes) (in oocyte cryopreservation) and embryos (in embryo cryopreservation). For years, glycerol has been used in cryobiology as a cryoprotectant for blood cells and bull sperm, allowing storage at liquid nitrogen temperatures. However, glycerol cannot be used to protect whole organs from damage. Instead, many biotechnology companies are researching the development of other cryoprotectants more suitable for such uses. A successful discovery may eventually make possible the bulk cryogenic storage (or "banking") of transplantable human and xenobiotic organs. A substantial step in that direction has already occurred. Twenty-First Century Medicine has vitrified a rabbit kidney to -135°C with their proprietary vitrification cocktail. Upon rewarming, the kidney was successfully transplanted into a rabbit, with complete functionality and viability, able to sustain the rabbit indefinitely as the sole functioning kidney.

In the context of cryonics, especially in preservation of the human brain, vitrification of tissue is thought to be necessary to prevent destruction of the tissue or information encoded in the brain. Currently, vitrification techniques have only been applied to brains (neurovitrification) by Alcor and to the upper body by the Cryonics Institute, but research is in progress by both organizations to apply vitrification to the whole body.