Anti-icing Coatings Based On PDMS With Patterned Or Lubricant Self-repairing Surfaces

Because of adverse impact brought by icing on substance surfaces in transportation,electricity,aviation and other fileds at high humidity and low temperatures,it is of crucial importance to seek anti-icing coatings with high performance to reduce the hazard of icing.In this work,based on polysiloxanes with low surface energy and low modulus,anti-icing coatings with patterned surface cross-linked by branched polydimethylsiloxane(b PDMS)or self-repairing lubricant polydimethylsiloxane modified polyurea polymer(PDMS-PU)were prepared.Moreover,the anti-icing performance and anti-icing mechanism were anticipated.Fluorinated polyhedral oligomeric silsesquioxane(F₅-POSS-H₃)with three silicon-hydrogen bonds and b PDMS were synthesized by hydrosilylation reaction.The patterned anti-icing coatings with surface microstructures were prepared by the breath figure method under a certain humidity and temperature.The mismatched modulus between the elastomer coating and ice could possibly cause local deformation when an external force was exerted,resulting in micro-cracks formed between the coating surface and ice.More importantly,microstructures on coating surfaces could facilitate stress concentration.There was only a small increase from 19.7±2.5 k Pa to 25.1±1.5k Pa in ice shear strength during the 30 icing/de-icing cycles.The wettability did not change significantly after the 30 icing/deicing cycles.In addition,excellent mechanical stability was exhibited during the wear test with the maximum ice shear strength of the coating,60.7±3.3 k Pa,which was less than 65 k Pa.Self-repairing lubricant anti-icing coatings were prepared from PDMS-PU by dissolving it in tetrahydrofuran as well as inert silicone oil with low molecular weight.The lubricant layer of silicone oil on the coating surface could prevent the interaction between ice and coating,and greatly reduce the ice shear strength.Moreover,the minimum ice shear strength of the lubricating anti-icing coating was low at about 2.9±0.3 k Pa.After subjected to 30 icing/deicing cycles,the minimum ice shear strength was only 17.2±4.6 k Pa.Due to the reversibility of hydrogen bonds in PDMS-PU,the coatings obtained superior self-repairing properties.Self-healing test results at room temperature and 60°C indicated that the prepared self-repairing lubricant anti-icing coatings could repair after physical damage.