Novel Robust Superhydrophobic Coating with Self-Cleaning Properties in Air and Oil Based on Rare Earth Metal Oxide

Herein, a simple spraying method was applied to prepare a novel robust superhydrophobic coating containing fluorinated hyper-branched polyurethane (F-HPU) resin and lanthanum oxide (La2O3). The composite coating had the maximum water contact angle (WCA) of 157 degrees and low sliding angle (SA) of 5.5 degrees when the content of La2O3 was 17%. Moreover, the composite coating can resist abrasion with sand paper for 80 cycles, which might be the reason that La2O3 particles adhered strongly on the substrate by the F-HPU resin with strong adhesion. Furthermore, the novel robust superhydrophobic coating can be applied in various substrates, resist water stream impact, and remain clean after being fouled by contamination in air and oil. Accordingly, the novel robust superhydrophobic coating has potential application in protection-needed materials. Meanwhile, we also provide a new application field for rare earth metal oxides and an alternative strategy for robust self-cleaning coatings.