Phase behavior and froth stability in a water/lysophospholipid system

Phase behavior in a water/lysophospholipid system was investigated. A hydrated solid phase is observed at low temperature. Above the melting temperature of the hydrated solid a micellar phase at low surfactant concentration and a liquid crystalline phase at high surfactant concentration were observed. Similarly to poly(oxyethylene)-type nonionic surfactant systems, clouding behavior takes place at high temperature. The concentration of micelle-liquid crystal transition shifts to higher surfactant concentration in acidic or basic condition, but polyhydric alcohol addition does not affect very much on this transition point. The effect of added inorganic salts on the phase behavior was also studied, and the change in melting temperature of the hydrated solid and the cloud point shows a trend of the order of Hofmeister series. At room temperature a solid phase and an aqueous phase are equilibrated and one can obtain rather stable froth by shaking the sample that may be stabilized by the adsorption of solid dispersions on the air-water interface. The effect of inorganic salts on the froth stability in the water/lysophospholipid system was studied. The inorganic salts with salting-out effect improved froth stability.