Durable Hydrate-phobic Coating with In Situ Self-Replenishing Hydrocarbon Barrier Films for Low Clathrate Hydrate Adhesion

Design of a Liquid Impregnated Surface with a Stable Lubricant Layer in a Mixed Water/Oil Environment for Low Hydrate Adhesion

Clathrate hydrate is a naturally occurring icelike solid that forms in the water phase under suitable temperature and pressure conditions in the presence of one or more hydrophobic molecules. It also forms inside the oil and gas pipes, leading to higher pumping cost, flow blockage, and even catastrophic accidents. Engineered surfaces with low hydrate adhesion can provide an effective solution to this problem. Liquid impregnated surfaces are examples of engineered surfaces that have already shown tremendous potential for reducing the nucleation and adhesion of solids. Here, we report the design and synthesis of liquid impregnated surfaces with extremely low hydrate adhesion under an oil and water mixed environment. The most challenging aspect of designing these surfaces was to stabilize a lubricant layer simultaneously under water and oil. A detailed methodology to make such lubricant-stable surfaces from a theoretical perspective was described and experimentally validated for lubricant stability. Experimental measurements on such surfaces showed extremely low hydrate accumulation and 1 order of magnitude or more reduction in hydrate adhesion force.

Multifunctional Amphiphobic Coating toward Ultralow Interfacial Adhesion of Hydrates

Hydrate adhesion is a challenging issue in some practical applications. However, most current anti-hydrate coatings fail to maintain their properties when subject to crude oil and corrosive contaminants. In addition, the effect of surface properties on the nucleation of hydrates is still unexplored from a microscopic perspective. In this study, a multifunctional amphiphobic PF/ZSM-5 coating consisting of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane modified ZSM-5 zeolite (F/ZSM-5) and adhesive polyethersulfone was fabricated by the spraying method. The interfacial nucleation and adhesion of hydrates on substrates were studied from a microscopic perspective. The coating exhibited excellent repellencies to various liquids, including water, edible oil, liquid paraffin, vacuum pump oil, n-hexadecane, and crude oil. The tetrabutylammonium bromide (TBAB) hydrate is readily nucleated on the bare Cu surface. In contrast, the coated substrate effectively inhibited the hydrate nucleation on the surface and even reduced the adhesion force to 0 mN/m. Furthermore, this coating was fouling- and corrosion-resistant and can maintain an ultralow hydrate adhesion force even after immersion in crude oil or TBAB solution for 20 and 300 d, respectively. The durable anti-hydrate performance of the coating was attributed mainly to the unique architecture and excellent amphiphobic properties enabling stable air cushions between the solid-liquid interface.

A Slippery Liquid-Infused Network-like Surface with Anti/De-icing Properties Constructed Based on the Phosphating Reaction

The excessive accumulation of ice seriously threatens various industrial facilities and production activities. Currently, slippery liquid-injected porous surfaces (SLIPS) have been developed as a new strategy for anti/de-icing; however, the lack of research on the adsorption and storage capacity for lubricating fluids has limited the development of SLIPS in the anti/de-icing field to some extent. In this work, a slippery liquid-infused phosphate network-like surface (SLIPNS) is prepared that adjusts the texture of the surface by varying the phosphating time to control the adsorption and storage of lubricating fluids. The as-obtained surface structure gives the SLIPNS excellent oil-storage/locked properties, can delay the freezing time of sessile droplets up to 436 s, which is almost 10 times that of an untreated aluminum sheet, and exhibits one-tenth the ice adhesion strength of untreated aluminum substrates (14.39 kPa). In addition, the SLIPNS shows effective durability and antifouling ability and has great potential in solving long-term anti/de-icing problems.