  Clathrate hydrate is a naturally occurring ice-like solid which forms in
water phase under suitable temperature and pressure conditions, in the presence
of one or more hydrophobic molecules. It also forms inside the oil and gas
pipes leading to higher pumping cost, flow blockage and even catastrophic
accidents. Engineered surfaces with low hydrate adhesion can provide an
effective solution to this problem. Liquid impregnated surfaces is one such
example of engineered surfaces which has already shown tremendous potential in
reducing the nucleation and adhesion of solids. Here we report the design and
synthesis of liquid impregnated surfaces with extremely low hydrate adhesion
under the mixed environment of oil and water. The most challenging aspect of
designing these surfaces was to stabilize a lubricant layer simultaneously
under the water and oil. A detailed methodology to make such lubricant stable
surfaces from theoretical perspective was described and experimentally
validated for lubricant stability. Experimental measurements on such surfaces
showed extremely low hydrate accumulation and one order of magnitude or more
reduction in hydrate adhesion force.
