王锋等- 挪威科技大学-Onion inspired anti-hydrate surfaces

Session 4 - Oral 2

Onion inspired anti-hydrate surfaces

 Feng Wang, Jianying He, Zhiliang Zhang *

NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway.

Abstract：Mitigating gas-hydrate formation and the subsequent gas-pipeline plugging is of crucial importance during the exploration and transportation of deep-water resources. Passive anti-hydrate surfaces that can inhibit hydrate formation directly on pipe walls or lower the adhesion between hydrates and solids without external force or energy inputs are desired. In this work, the onion film that consists of monolayer epidermal cells was found to be accountable for the low adhesion of onion bulb scales to solids. Firstly, the sub-surface porous structures led to interface stiffness inhomogeneity and initiated interface cracks. Secondly, the surface cuticle layer acted as hydrophobic lubricant for lowing the adhesion. Inspiring by the onion film with low adhesion to solids, an elastomer film with smooth surface and sub-surface micropatterns was introduced. With the onion inspired film, the cyclopentane hydrate adhesion strength on glass was decreased dramatically from 95 kPa to 4.7 kPa. Importantly, the hydrate adhesion strength on the onion inspired surface maintained super low (8.7 kPa) after 20 cyclic tests. Integrating a regenerable artificial cuticle layer enabled even lower hydrate adhesion (2.9 kPa) on this film. The onion inspired surface therefore is promising for future hydrate mitigation.

Keywords: Gas hydrate, onion film, hydrate adhesion strength, anti-hydrate surface.