Investigating the wetting phenomena and fabrication of sticky, para-hydrophobic cerium oxide coating

We report fabrication of a novel sticky parahydrophobic cerium oxide (CeO2) coating using a facile and industrially viable plasma spray technique, which has prospective applications in microfluidic chips, no loss microdroplet transportation and chemical microreactors. Our coating displays significantly high water contact angle (∼159.02˚) along with high contact angle hysteresis (CAH≥90˚), very much similar to a ‘Rose petal’. This is further strengthened by the fact that the coating displayed remarkable adhesion even with large inverted water droplets of 70 μL, which is significantly higher than the reported values of 18 μL for polymer and 20 μL for drop casted CeO2 nanotubes. We also present systematic characterization results to clarify the ongoing confusion regarding the hydrophobicity of CeO2 coatings often reported in literature. Meanwhile, our parahydrophobic coating also showed remarkable thermal and mechanical stability even at a significantly high temperature of 200 °C for 14 h and with 50 g abrasive paper.