CO₂ Sequestration by Bile Salt Aqueous Solutions and Formation of Supramolecular Hydrogels

Bubbling carbon dioxide (CO2) into aqueous solutions of bile salts such as sodium deoxycholate caused a gelation of the solution, forming a hydrogel made of entirely natural biological molecules and providing a convenient storage reservoir of CO2 in water. The carboxylate group of the bile salt becomes protonated in the aqueous solutions to make the bile acid only marginally soluble in water, which induces the formation of a supramolecular...