Micro/nanostructure And Superwetting Behavior Of Bionic Slippery Surfaces

Inspired by the microstructure and composition of the surface of the lotus leaf,the researchers prepared a superhydrophobic surfaces(SHSs)that exhibited excellent unwetting to water,which is primarily due to the formation of a stable gas layer structure between the solid-liquid interface.However,the structure of the airbag structure is metastable,and the SHSs are prone to failure under high temperature,high pressure and other physical damage,so it is important to find a hydrophobic surface with high stability.Based on the principle of bionics,researchers studied the ultra-slip behavior of the pitcher plant and injected a low surface energy lubricating fluid into the micro/nano structure substrate to synthesize a liquid-injected porous slippery surface.The surface has excellent low adhesion,anti-icing,self-healing and the like,and has received extensive attention.Due to the nature of the liquid lubricating fluid,the stability of such surfaces needs to be improved.In addition,there has been no research on low adhesion surfaces of deep eutectic solvent-type ionic liquids(DESs),which will reduce the transfer loss of viscous ionic liquids and achieve micro-liquid handling.In view of the above problems,this study carried out micro-nanostructured construction of slippery surface,and successfully obtained high stability hydrophobic slippery surface and superDESphobic surface,and the structure and properties of the above surface were carefully analyzed.The main research contents and results of this paper are as follows:(1)The superhydrophobic(Ni,Co)-(CO3)0.5(OH)0.11H2O coating(NiCo-NCA)was prepared by hydrothermal method and surface modification.The slippery surface was successfully prepared by injecting ionic liquids,1-octyl-3-methylimidazolium hexafluorophosphate and 1-butyl-3-methylimidazolium hexafluorophosphate into the superhydrophobic NiCo-NCA substrate.In the high-temperature heat treatment and heating/cooling cycle experiments,the prepared slippery surface maintained a sliding angle of 6±2° even at a high temperature of 240℃,while the SHS failed.In addition,hot water(-95 ℃)and condensed water droplets can easily slide off on slippery surfaces.Thanks to its self-healing ability,which allows it to quickly recover its non-wetting properties after physical damage,even under external impact.(2)A novel non-wetting surface Ag-CuF/M with superDESphobic properties was prepared on a copper foam substrate by a simple two-step method.The contact angles(CAs)of the six DESs and their derivatized solutions with different surface tensions on the Ag-CuF/M surface were all greater than 150 °,and the sliding angles(SAs)were all below 5 °.The superDESphobic surface maintains excellent unwetting performance at 120 ℃ or external impact.In addition,it has been found that the superDESphobic surface can significantly delay the DESs freezing and effectively reduce the adhesion strength on the surface after DES freezing,showing excellent anti-freezing performance for DESs.