Nanoscale surface engineering for reducing gas hydrate adhesion

Gas hydrate deposition and adhesion to inner pipeline walls significantly challenge the safety and efficiency of natural gas exploration and transportation systems. Effective material-based passive anti-hydrate solutions are urgently needed to replace the conventional methods, which are costly and environmentally unfriendly. Understanding how hydrates interact with rough solid surfaces is essential to developing these solutions. This study investigates the solidification and detachment processes of gas hydrates on rough solid surfaces from the perspective of nanomechanics using molecular dynamics (MD) simulations. The effects of surface roughness on hydrate adhesion at various interfacial gas contents and temperatures have been systematically explored. Unlike macroscale roughness, which typically increases adhesion strength due to enlarged contact areas and mechanical interlocking, our findings show that nanoscale roughness can act as interface crack initiator, weakening the adhesion strength. The results demonstrate the feasibility of reducing hydrate adhesion through surface engineering, suggesting that designing optimal surface roughness can serve as a novel strategy for fabricating anti-hydrate materials. Furthermore, a relationship between hydrate adhesion strength and nanoscale interfacial structures has been established, which can be encapsulated as a classifier. This classifier can facilitate large-scale screening for promising anti-hydrate surface materials through machine learning.