Meniscus inspired flexible superhydrophobic coating with remarkable erosion resistance for pipeline gas transmission

Inspired by human meniscus, a superhydrophobic inner pipeline coating with has been developed to mitigate the erosion and corrosion damages to gas transportation pipeline. The erosion-resistant coating, consisting of modified TiO2 nanoparticles (NPs), multi-walled carbon nanotube (CNTs), and epoxy resin (EP), is built on a buffer layer made of polydimethylsiloxane (PDMS). The optimized buffer layer thickness (100 μm) was determined by finite element simulation when mixing ratio between the curing agent and PDMS was 1:30. The erosion resistance of the prepared coating was quantified by an erosion ring experiment. Finally, erosion resistance of materials produced by different filler types (fibrous and spherical) were compared. The erosion resistance of the material is significantly improved by the tensile force of the fiber filler, similar to the steel in reinforced concrete. The result shows that the buffer-structure coating can reduce the magnitude of erosion rate significantly. Compared to the coating with no buffer structure, the maximum reduction of erosion rate is up to 37.55 %. In addition, the water contact angle (CA) of the sample could maintained over 150° after various mechanical shocks, such as 350 times of 90° bending test, 1500 times of sand impact test, and 4H pencil hardness test. Compared with the 316L steel sample, the corrosion potential of the coating in 3.5 wt% NaCl solution increased from −0.18 V to 0.04 V, making it potentially applicable for the corrosive environment of submarine pipelines.