Thermal spray for durable and large-area hydrophobic and superhydrophobic/icephobic coatings

A method of forming a polymeric hydrophobic coating on a substrate by a high velocity oxygen fuel (HVOF) thermal spray deposition process, comprising:

• feeding a HVOF thermal spray torch with polymeric particles, the polymeric particles including at least 50 weight percent of polyether ether ketone (PEEK) particles, the polymeric particles having an initial particle morphology;
• heating the polymeric particles with the HVOF thermal spray torch;
• controlling a heating temperature of the HVOF thermal spray torch to obtain a mixture of partially melted polymeric particles, which retain a fraction of the initial particle morphology, and fully unmelted polymeric particles, which fully retain the initial particle morphology, wherein controlling the heating temperature of the HVOF thermal spray torch comprises adjusting deposition parameters of the HVOF thermal spray deposition process including adjusting a fuel-to-oxygen ratio of the HVOF thermal spray torch to between about 0.5 to about 0.9, adjusting a fuel feed rate of the HVOF thermal spray torch to between about 1.5 to about 2.2 gallons per hour (GPH), and adjusting an oxygen feed rate of the HVOF thermal spray torch to between about 600 to about 900 standard cubic feet per hour (SCFH);
• accelerating the polymeric particles toward the substrate using the HVOF thermal spray torch;
• and
• impacting the substrate simultaneously with the partially melted polymeric particles and the fully unmelted polymeric particles to form the polymeric hydrophobic coating with an average surface roughness of between about 1 nanometer and about 100 micrometers, the coating further having a water contact angle of 90° or more.