Israeli Scientists Develop "Super Ice" Stronger Than Concrete

Researchers at the Hebrew University of Jerusalem have engineered a novel material, dubbed BioPykrete, which is ten times stronger than regular ice and comparable in strength to concrete. This innovation could potentially serve as a substitute for concrete in cold, polar environments.

The concept of reinforcing ice dates back to World War II with the creation of pykrete, a mixture of ice and sawdust. This material was strong and inexpensive, and even a prototype ship was built from it, though it required refrigeration in warmer waters.

The new approach, detailed in the journal Colloids and Surfaces B: Biointerfaces, involves mixing ice with nanocellulose crystals. A specially designed chimeric protein acts as a molecular glue, binding the ice and cellulose together to form a robust, crack-resistant three-dimensional network upon freezing. This protein has one part that bonds with ice and another that bonds with cellulose.

Professor Ido Braslavsky, a co-author, explained that the goal was to control the bonding of materials at the molecular level, moving beyond simple fiber mixing. This resulted not only in increased strength but also altered the material's failure mode; instead of shattering, it deforms gradually. The cellulose network and protein bridges in BioPykrete impede and redirect cracks, preventing the rapid propagation seen in ordinary ice.

Laboratory compression tests showed BioPykrete's strength to be on par with conventional concrete. The addition of the engineered protein doubled the material's strength compared to a simple ice and cellulose mixture. The researchers envision BioPykrete as an eco-friendly and biodegradable alternative for construction in the Arctic and Antarctic, where transporting traditional materials like steel and concrete is prohibitively expensive.