Interfacial mechanical properties of tetrahydrofuran hydrate-solid surfaces: Implications for hydrate management

Understanding the interfacial mechanical properties between hydrate and solids is vital to designing and fabricating surfaces for hydrate management. Herein, the role of the surface wettability, the type of solid substrate and temperature on the interfacial adhesion properties of tetrahydrofuran (THF) hydrate and ice were examined by force analysis based shearing measurements and molecular dynamics (MD) simulations. The results showed that the adhesion strength of THF hydrate and ice on silica varies with the compositions of coating, and the adhesion strength of ice is larger than that of THF hydrate for all investigated solid substrates. Particularly, in contrast to a linear relationship between 1 + cosθ_r and hydrate adhesion on organic silanes/thiols/polymer surfaces, the hydrate adhesion on the coated inorganic glass surfaces is enhanced as a function of 1 + cosθ_r, in which θ_r is the receding contact angle. MD simulations uncovered that the adhesion strength of ice on solid substrates is dominated by the quasi-liquid water layer, however, that of hydrate is governed not only by the quasi-liquid layer but also newly formed unconventional clathrate cages. This study provides new insights and perspectives into the hydrate adhesion on solid surfaces, which is of help to develop hydrate-phobic coatings for advanced hydrate management.