735b Role of Sodium Dodecyl Sulfate at Hydrate/liquid Interface

Junshe Zhang1, Chi Lo2, Alexander Couzis3, Jae W Lee3, Ponisseril Somasundaran4, and S. Lu5. (1) Chemical Engineering Dept, The City College of New York, 140th St and Convent Ave, New York, NY 10031, (2) Chem Eng Dept, The City College of New York, 140th St and Convent Ave, New York, NY 10031, (3) The City College of New York, 140th St and Convent Ave, New York, NY 10031, (4) Columbia University, Room 911, Mudd Bldg., 500W 120th Street, New York, NY 10027, (5) Earth and Environmental Eng, Columbia University, Room 911, Mudd Bldg., 500W 120th Street, New York, NY 10027

Clathrate hydrates are non-stoichiometric crystalline compounds in which small guest molecules such as methane, carbon dioxide, and tetrahydrofuran (THF) stabilize the hydrogen-bonded water cavities. One volume of gas hydrates can store up to 170 volumes of gas at STP conditions. Gas hydrate formation generally favors low temperature and high pressure (< 300 K and > 0.1MPa). Gas hydrates have a good potential for gas storage compared to compressed forms or liquefied forms. One obstacle to actual practice of gas hydrate technology is the long formation period. Many studies have found that sodium dodecyl sulfate (SDS) reduces the induction time and accelerates the growth rate. The role of SDS in promoting hydrate formation is still elusive. One possible explanation is that SDS molecules adsorb on hydrate crystals that reduce the energy barrier of hydrate nucleation. Understanding the interaction between SDS and hydrates can clarify the promoting effect of SDS on gas hydrate kinetics. This presentation will provide the adsorption behavior of SDS on THF hydrates and its relationship with the hydrate nucleation in terms of z-potential and pyrene fluorescence measurements.