Nanowerk March 12, 2022
Superabsorbent polymer gels can absorb large amounts of water (100–1000× their dry weight). However, gels that are both superabsorbent and able to expand rapidly have not yet been realized. Researchers at the University of Maryland created such gels by in situ foaming of a monomer solution (acrylic acid and acrylamide) using a double-barreled syringe which has acid and base in its two barrels. The gas generated by the acid–base reaction, was stabilized by an amphiphilic polymer in one of the barrels. The monomers are then polymerized by UV light to form the gel around the bubbles, and the material was dried under ambient conditions to give a porous solid. When water was added to the dry gel, it absorbed water at a rate of 20 g/g·s until an equilibrium is achieved at ∼300× its weight. Gel dimension increased by ∼20%/s ending in e more than 3 times its original size. It had a porosity of >90% and an interconnected network of pores and power density of 260 mW/kg. The work could enable new designs for mechano-chemical engines and potentially for artificial muscles…read more. TECHNICAL ARTICLE
Graphical abstract. Credit: ACS Appl. Mater. Interfaces 2022, XXXX, XXX, XXX-XXX, March 9, 2022Â