Preparation And Properties Of Fast Self-healing Superhydrophobic Materials

Superhydrophobic surfaces are widely used in self-cleaning,anti-corrosion and other fields,but durability is often threatened by the external environment.In the process of use,it is inevitable to be worn or slowly oxidized by air,resulting in the decline of superhydrophobic performance.Therefore,prolonging the durability of superhydrophobic surface in the application process has become an urgent problem to be solved.At present,the recovery of superhydrophobic property can be realized through the migration of low surface energy material.However,if it is placed in the external environment for self-healing,there are problems of slow heal speed and long heal time,which still can not meet the needs of rapid self-healing of superhydrophobic surfaces in practical application scenarios.In this paper,polyurethane（PU）sponge was used as the substrate,polyaniline（PANI）and multi-wall carbon nanotubes（MWCNTs）were used as the thermal conversion materials,and photocatalytic nanoparticles（PDA@WO₃ NPs）were used to construct the surface rough structure with polydimethylsiloxane（PDMS）as adhesive and heal agent.The self-healing superhydrophobic sponge（PDA@WO₃/MWCNTs/PDMS/PANI@PU）with a strong coating was constructed by in-situ growth and adhesive coating.The self-healing superhydrophobic sponge has good superhydrophobicity,and its water contact angle（WCA）can reach 155°.At the same time,it shows excellent chemical stability and mechanical durability,withstanding chemical corrosion and physical wear to a certain extent.The self-healing superhydrophobic sponge has excellent photothermal/Joule-heat thermal conversion ability.Under the irradiation of a standard sunlight（1.0 k W/m²）for 20 s,its equilibrium surface temperature（EST）can quickly reach 104.9°C.By supplementing an additional 18 V voltage,the EST of the modified sponge surface exceeds 120°C.In addition,the modified sponge loses its superhydrophobic property after 1 min of O₂ plasma etching,due to the rapid migration of low surface energy polydimethylsiloxane（PDMS）chain under simulated sunlight,the WCA of self-healing superhydrophobic sponge can quickly recover to155°after 1.0 k W/m² simulated sunlight for 2 min.The modified sponge also shows significant anti-fouling ability to particulate pollutants and organic pollutants,which prolongs the service life.The self-healing superhydrophobic sponge can be applied in many fields,such as oil-water separation,viscous oil treatment,seawater desalination,de-icing and anti-icing.