Preparation And Study Of Superhydrophobic Surface With Anti-icing Ability

Icing often causes great inconvenience to daily life and economic activities and even threatens the safety of people.However,the traditional strategies,such as thermal heating,chemical methods,mechanical action,are far from satisfying due to their low efficiency,high economic consumption and high-energy consumption.They may also cause equipment damage,pollution and ecological concerns.Therefore,an effective,low-cost and eco-friendly anti-icing strategy is still highly desirable.Bio-inspired superhydrophobicity is found to be an efficient,low cost,and eco-friendly anti-icing strategy because of its novel surface structure and repellence to liquid water.However,the superhydrophobic surface often suffers from poor mechanical durability because its microstructure is easily damaged by external forces,leading to the degeneration of anti-icing ability.In addition,the ice adhesion prevents the superhydrophobic surface from spontaneous removal of the deposited ice.In this study,we fabricated the superhydrophobic surfaces with mechanical robustness and low ice adhesion by the structural design and morphology control.The as-prepared surface exhibits durable anti-icing/deicing capability and spontaneous removal of ice.The finding provides a strategy for fabricating superhydrophobic surface with durability and spontaneous removal of ice.A highly compressible and stretchable superhydrophobic surface was fabricated by a layer-by-layer deposition of polydopamine(PDA)and Ag nanoparticles on the polyurethane(PU)sponge.The resulting sponge shows mechanical robustness because it can bear 6000 cycles of mechanical compression and 2000-cycle tensile measurements without losing its superhydrophobicity.The mechanical robustness can be assigned to the strong interactions between the Ag nanoparticles,PDA layer and the sponge.It also shows excellent anti-icing property by delaying water droplets into ice for ~10000 s.Moreover,it can still keep the anti-icing property with a similar delay time of ~9300 s after 4000-cycle compressions.A superhydrophobic surface with low ice adhesion was fabricated through the self-polymerization of dopamine and subsequently deposition of Ag nanoparticles.The ice adhesions are related to the morphologies of superhydrophobic sponges,which can be controlled by changing the concentration of silver ammonium.The superhydrophobic surface was able to shed off the ice formed on its surface by mechanical compression or cold wind,exhibiting a low ice adhesion of 166.6 Pa.The ice/deicing process could be repeated for more than 90 cycles.For spontaneous removal of ice and suppress of frosting,a hybrid superhydrophobic surface was fabricated by integrating a superhydrophobic copper mesh and an intelligent organogel with self-secretion capability.The organogel was synthesized by incorporating ethylene glycol and water into three-dimensional(3D)polyvinyl alcohol(PVA)based network cross-linked by dynamic borate ester bonding.The secreting rate of the anti-freeze agent was dependent on the content of carboxylic content and cross-linking density of the organogel.When the carboxylic content was higher than 0.73 wt%,the PVA based organogel was stable at room temperature,while it secreted the anti-freeze agent autonomously at subzero temperature.Owing to the self-secretion capability,the hybrid surface effectively suppressed the frosting and significantly decreased the ice-adhesion to 8 Pa.Because the secreted anti-freeze agent could migrate to the superhydrophobic surface/ice interface under the action of capillary force,the deposited ice melted and then spontaneously shed from the hybrid superhydrophobic surface.The surface was found to be intact after 5 cycles of icing/deicing.