Methane Hydrate Formation on Hydrophilic Zr⁴⁺/D-Gel-Coated Surfaces

During the production and transportation of natural gas, hydrate formation and accumulation in pipelines can lead to blockages, resulting in gas leakage, economic losses, and safety hazards. Recently, the development of superhydrophobic antigas hydrate coatings for pipelines has been identified as an effective strategy to mitigate pipeline plugging. Although superhydrophobic surfaces can effectively reduce the adhesion strength of hydrates to the wall, they tend to promote surface gas enrichment and water molecule ordering, thereby accelerating hydrate nucleation and growth. Furthermore, the microstructure of superhydrophobic surfaces is relatively fragile and susceptible to damage, which limits their long-term stability and reliability. This study proposes a hydrophilic gel coating, Zr4+/DMSO-Gel, which can delay the nucleation induction period of methane hydrates on solid surfaces and reduce their growth rate. Microscopic observations revealed that the coating induced partial decomposition of methane hydrate, resulting in the formation of a large water layer, which can reduce wall adhesion. Furthermore, Raman spectroscopy was employed to analyze the structure of surface water molecules, revealing the mechanism by which the coating inhibits hydrate formation. The results showed that strong hydrogen bonding interactions between the coating surface and water molecules resulted in the predominance of bound water (BW) on the surface, while the proportion of tetra-coordinated hydrogen-bonded water (4-HBW) was reduced, thereby inhibiting the formation of hydrate cage structures. These findings not only provide a novel approach for the development of hydrate-resistant coatings but also offer new insights into antiplugging strategies for natural gas pipelines.