Hokkaido University’s ongoing research into hydrogels has borne fresh fruit: a new polymer-based material that, unlike other polymers, hardens when heated – by 1,800 times.
At room temperatures the substance is a soft see-through gel. But heated to 60° C (140° F), it hardens, turns opaque, and becomes strong enough to lift a 10-kg (22-lb) weight.
Hokkaido researchers Takayuki Nonoyama and Jian Ping Gong were apparently inspired by natural proteins that stay stable inside thermophiles – organisms living in extremely hot environments like springs or deep-sea thermal vents. Such proteins would ordinarily denature, but those inside thermophiles have adapted to the high temperatures to stay stable.
The team was able to develop a cheap, safe polyacrylic gel by dunking polyacrylic acid into a calcium acetate solution. “Polyacrylic acids are used in disposable diapers and calcium acetates are used in food additives,” Jian Ping Gong explains in a press release.