Efficient fabrication of lightweight polyethylene foam with robust and durable superhydrophobicity for self-cleaning and anti-icing applications

The poor robustness and durability of superhydrophobic surfaces under various externally imposed stresses have become a challenging issue for practical applications. Here, an efficient dissolution and modification strategy is proposed for facilely fabricating superhydrophobic polyethylene (F-PE/SiO2) foam with 98.6% porosity using sodium chloride (NaCl) as a sacrificial template and superhydrophobic nano-silica particles as a surface chemical modifier. A microscale porous and interconnected 3D framework is formed when NaCl is dissolved and the nanosilica particles adsorb on the surface of interconnected pores to form nanoscale structures. The F-PE/SiO2 foam exhibits a water contact angle (CA) of 158 +/- 2 degrees and a sliding angle (SA) of 4 +/- 2 degrees. Interestingly, the F-PE/SiO2 foam could maintain its superhydmphobicity under 980 Pa pressure of water droplet impacting and 8.1 kPa pressure of water flow impacting. Besides robust dynamic superhydrophobicity, the F-PE/SiO2 foam exhibits exceptional mechanical durability against knife scratching, tape-peeling, bending-twisting, and ultrasonication in ethanol because of unique hierarchical micro-nanostructure and the stably adsorbed nano-silica particles. Impressively, the F-PE/SiO2 foam maintains superhydrophobicity upon abrasion damage until all the thickness is worn away, which are potentially advantageous in practical applications. Moreover, this F-PE/SiO2 foam also demonstrated excellence in anti-wetting, self-cleaning and anti-icing, which makes the product can effectively reduce the damage caused by surface pollution, ice formation, and other natural factors when applied to oil-water separation and insulation material of refrigerator.

Automated summary

The study proposes an efficient method to fabricate superhydrophobic polyethylene foam with high porosity and exceptional durability. The foam maintains superhydrophobic properties under water pressure and flow impact, demonstrating excellent mechanical performance and potential for various applications.