Inhibiting The Nucleation,Aggregation Of Hydrates And Anti-Crude-Oil-Adhesion With Superwetting Interface

The increasing demand for energy has forced oil and gas extraction from the mainland to the deep sea.However,as the main mode of transportation,oil and gas pipeline transportation has been plagued by high viscosity crude oil,wax deposition,nucleation and aggregation of hydrates.The major reasons of pipeline blockage in oil and gas transportation varies depending to the different transport medium.Traditional methods of preventing and controlling pipeline clogs,such as mechanical scraping,pipeline heating,and chemical reagents,are high costs,ineffective,challenging to separate,and inadequately environmentally friendly,and do not match the criteria of a sustainable green economy.One of the most crucial problems to be resolved is how to reduce pipeline blockages and guarantee the safe exploitation and transmission of oil and gas resources.In this paper,based on the anti-adhesion mechanism of super-wetting materials and the mechanism of hydrate nucleation inhibition by inhibitory functional groups,we prepare super-wetting materials with different functions by designing the micro-nano structures and regulating surface chemistry of super-wetting materials to deal with the blockage problems of oil and gas pipelines.The main work is as follows:To address the problems that the micro-nano structures of superamphiphobic surface are often wetted by condensing water and oil droplets under low temperature conditions or hot fluids under high temperature conditions,resulting in the loss of superamphiphobic performance,we report a superamphiphobic P（HFIO）@Si O₂@SS with ultra-low surface energy and a high aperture ratio pore structures（denoted as the PSSH）to resist water/oil-droplet-condensation and repel hot fluids.Compared to stainless steel（SS）or low pore size ratio superamphiphobic materials,there are no condensate droplets wet the PSSH surface during condensation of water droplets（over 180 min）or distillation of crude oil（over 500 min）,showing excellent anti-condensation properties.In addition,PSSH has excellent anti-adhesion and drag reduction properties for crude oils in the temperature range of 25-70°C.Its interconnected high aperture ratio pore structures and ultralow surface energy fluorinated side chains enhance the sliding resistance of droplets to micro-nanostructures and the driving force for condensate droplets to spontaneously roll away from its surface.In addition,compared with the SS,PSSH reduces adhesive force to hydrates（3.2°C）and wax（25°C）by 92.1%and89.4%,respectively.The PSSH demonstrates the great potential in handling pipeline blockage and improving the transport efficiency of fluids,offering alternative strategy to prepare superamphiphobic surfaces for oil and gas transportation,heat transfer,and other applications.The superamphiphobic surfaces with anti-crude oil and hydrate adhesion properties can induce ordered arrangement of surface water molecules and promote new hydrate nucleation,while grafting inhibition functional groups onto the surfaces of two-dimensional materials can delay hydrate nucleation,but the grafting density makes the inhibition effect poor,and the loss of its inhibition performance as a result of contamination by crude oil adhesion is disregarded.ignored.To address these problems,we designed a polymer（P（PIDHN））with abundant inhibition of functional group,blended it with hydrophilic silicon dioxide（Si O₂）to obtain a superhydrophilic coating（P（PIDHN）@Si O₂）and coated it on the surface of 3D open-cell Ni foam to obtain a superhydrophilic material（P（PIDHN）@Si O₂@Ni foam）with a high concentration of inhibition functional groups.Molecular dynamics simulations show that the hydrophilic functional group of the P（PIDHN）can bond with water molecules and form hydrated liquid film,reduce the hydrogen bond stability in the system,disrupt the orderly arrangement of water molecules,and efficiently inhibit hydrate nucleation and reject crude oil.The results showed that the induction time of Ni foam was shortened by 48.9%compared with the blank system,while the induction time of P（PIDHN）@Si O₂@Ni Foam was prolonged by427.7%,showing excellent inhibition performance of hydrate nucleation.The in-situ DSC and Raman further demonstrated that the surface inhibitory functional groups can bond with water molecules to lower the nucleation temperature of hydrates and disrupt the orderly arrangement of water molecules to inhibit hydrate nucleation.More importantly,the materials not only prevented light crude oil from adhering to the P（PIDHN）@Si O₂@Ni Foam surface,but also for highly viscous heavy crude oil.Compared with unmodified Ni foam,P（PIDHN）@Si O₂@Ni Foam reduced the adhesion of crude oil by 93.3%.This study provides references for the development of materials to prevent pipeline from blockage in aqueous phase dominated oil-gas transportation systems.In gas-phase（gas-water）dominated or gas-solid（gas-hydrate particles）systems during hydrate extraction,the key to solving pipe blockages is to simultaneously inhibit fresh hydrate nucleation and prevent formed hydrates from adhering to the pipe wall.Inspired by glass sponges,anti-erosion 3D porous superhydrophobic materials（P（HHIP）@Si O₂@Ni foam）with the ability of inhibiting hydrate nucleation have been prepared to resolve the conflict between superhydrophobic surfaces and the promotion of hydrate nucleation.The high specific area 3D porous skeleton allows for an increase in the content of the side chain terminal hydroxyl group（inhibitory groups）without weakening the superhydrophobic properties,thus achieving inhibition of nucleation of fresh hydrates and anti-adhesion of nucleated hydrates.Molecular dynamics simulations show that the side chain terminal hydroxyl group on the superhydrophobic surface bond to water molecules via hydrogen bonding,reducing the stability of hydrogen bonds between water molecules,disrupting the orderly arrangement of water molecules,and retarding the formation of hydrate cages.The experimental results show that compared with the SS,the induction time of hydrate formation was prolonged by 84.4%and hydrate adhesive force was reduced by 94.2%.Furthermore,the exterior cavities of the skeleton form vortices by reducing flow rate to prevent the erosion of terminal hydroxyls located on the inner cavities surface,displaying excellent inhibition and anti-adhesion properties even after erosion for 4 h at 1500 rpm.Therefore,this research paves the way towards developing super-wetting materials applied in oil and gas industry,carbon capture and storage,etc.