Remarkable antiagglomeration effect of a yeast biosurfactant, diacylmannosylerythritol, on ice-water slurry for cold thermal storage

Antiagglomeration effects of different surfactants on ice slurry formation were examined to improve the efficiency of an ice-water slurry system to be used for cold thermal storage. Among the chemical surfactants tested, a no nionic surfactant, poly(oxyethylene) sorbitan dioleate, was found to show a greater antiagglomeration effect on the slurry than anionic, cationic, or amphoteric surfactants. More interestingly, diacylmannosylerythritol, a gly colipid biosurfactant produced by a yeast strain of Candida antarctica, exh ibited a remarkable effect on the slurry, attaining a high ice packing fact or (35%) for 8 h at a biosurfactant concentration of 10 mg/L. These nonioni c glycolipid surfactants are likely to effectively adsorb on the ice surfac e in a highly regulated manner to suppress the agglomeration or growth of t he ice particles. This is the first report on the utilization of biosurfact ant for thermal energy storage, which may significantly expand the commerci al applications of the highly environmentally friendly slurry system.