Anti-icing performance of the superhydrophobic surface with micro-cubic array structures fabricated by plasma etching

We designed and constructed a series of micro-cubic arrays on silicon surface by means of a selective plasma etching technology to explore the size effect of surface microstructure on anti-icing/icephobic performance in terms of ice adhesion strength and icing delay time in this work. It was confirmed that the micro-cubic array with the center-center spacing distance of 70 mu m could greatly delay the icing process to 1295s (similar to two orders of magnitude comparing with that on the substrate surface). This type of micro-structures could entrap more air pockets underneath the water droplets to form the stable Cassie-Baxter wetting state, leading to lower actual solid/liquid contact areal fraction similar to 8.15% and larger heat transfer barrier. Meanwhile, the special interface configuration is beneficial to the reduction in ice adhesion strength. As the temperature decreases, the wetting state with varied has shifted. The ice adhesion strength of the surface was as low as 16kPa with the center-center spacing distance of 30 mu m for the micro-cubic arrays. In this case, the entrapped air pockets act as the microcracks under the shear force, which leads to lower fracture critical stress. The understanding of the size effect of microstructures on the icing delay ability and ice adhesion strength will be beneficial to the design of ideal antiicing/icephobic materials.