The solubilization of naphthalene using tea saponin as a biosurfactant: Effect of temperature

Due to the benign features of biosurfactants such as their low toxicity and desirable biodegradability, there has been growing interest in developing these materials for environmental remediation applications. In this work, the relationship between the temperature and the solubilization of tea saponin was investigated via critical micelle concentration (CMC), particle size, and thermodynamics measurements. In addition, the aqueous solubility enhancements of naphthalene provided by micellar solutions of biosurfactants (tea saponin) and a synthetic surfactant (Tween 80) were measured and compared. Results indicated that the solubilization effect of tea saponin increased as the temperature was elevated from 298 to 313 K, which thus indicated that this effect had a strong dependence on temperature. An increase in the temperature also led to a lower CMC value, an increase of the particle diameter, and an enhancement of the molecular activity, which thus led to the enhanced solubilization effect of tea saponin. Moreover, the solubilization effect of tea saponin was better than that provided by Tween 80. The results confirmed the potential applicability of tea saponin for enhanced remediation of naphthalene.