Spontaneous\nLifting and Self-Cleaning of Gas Hydrate\nCrystals

Crystal\nfouling, which refers to the accumulation of precipitates\non surfaces and the associated damage, is a common problem in many\nindustrial processes. In deepwater oil and gas transportation, hydrate\nblockage poses as a considerable barrier. Consequently, modifying\nhydrophobicity of surfaces has become an increasingly focused strategy\nto mitigate hydrate. However, the design of surfaces that effectively\ncontrol the hydrate remains challenging. Herein, we report a superior\nsmooth anti-hydrate material based on silanized modification. The\nlow-adhesion silanized silicon wafer (SSW) realizes a win–win\nstrategy of hard formation and easy removal. Through a comprehensive\nstudy combining experimental validation with theoretical analysis,\nthe unique characteristics of SSW in the field of anti-hydrate surfaces\nwere deeply discussed. Various hydrate crystals exhibited a completely\ndifferent hydrate growth mode at the SSW surface, in which hydrate\ncrystals spontaneously elevated and lifted themselves off from the\nsurface. The presence of the fluorine element on the SSW surface allowed\nself-lifting growth of hydrate crystals after they covered the water\ndroplet. And the loose and porous crystal structure in this self-lifting\ngrowth could reduce the contact area between the hydrate crystals\nand the substrate, allowing the crystals with minimal adhesion force\nand removal disturbance. Furthermore, the gas enrichment on the SSW\nsurface also reduced the contact with the substrate, thereby decreasing\nthe adhesion and allowing self-cleaning behavior. These results indicate\nthat the silanized surface is a promising candidate for developing\nanti-hydrate materials for hydrocarbon production and transportation\nindustry.