Surfactants have been used as hydrate promoters. This work presents the adsorbed amount and self assembled layers of both cationic and anionic surfactants on cyclopentane (CP) hydrates. The adsorption isotherms of SDS and DTAB exhibit an L-S type isotherm on CP hydrates. By identifying these isotherms, one can determine how hydrates form under the influence of surfactants. We proposed that surfactant structures reduce the energy barrier of hydrate nucleation by adsorbing onto hydrate nucleus surface1. These adsorbed layers can also influence water structure, by adding surface charge2 and changing the microenvironment of hydrate particles3. In terms of zeta potentials and equilibrium isotherms, we will explain an adsorption mechanism of surfactant on the hydrate –water interface.
References 1. Zhang, J. S.; Lee, S. Y.; Lee, J. W. Kinetics of methane hydrate formation from SDS solution. Ind. Eng. Chem. Res. 2007, 46, 6353-6359. 2. Lo, C.; Zhang, J. S.; Somasundaran, P.; Couzis, A.; Lee, J. W. Adsorption of surfactants on two different hydrates. Langmuir 2008, 24, 12723. 3. Zhang, J. S.; Lo, C.; Somasundaran, P.; Lu, S.; Couzis, A. ; Lee, J. W. Adsorption of Sodium Dodecyl Sulfate at THF Hydrate/Liquid Interface. J. Phys. Chem. C 2008. 112. 12381.