Fabrication of a durable omniphobic thin film and its application in precision nozzles

Abstract

The ultrafine nozzles used in micropatterning processes easily encounter various pollutions, such as clogging, liquid clumping, and bond tailing, on the nozzle surfaces. In this study, an omniphobic functional film was developed by an initiated chemical vapor deposition (iCVD) method and used to fabricate an antifouling nozzle. In the iCVD process, polymeric fluorine films were grown under optimized conditions, and their durability was analyzed through abrasion and nanoscale cutting tests to evaluate the surface wear resistance and adhesion strength, respectively. Two omniphobic films, prepared using homopolymer p(C6FMA) and copolymer p(C6FMA-co-DVB), were compared; the p(C6FMA-co-DVB) film was determined to have a superior durability than the p(C6FMA) film. Consequently, the p(C6FMA-co-DVB) film was deposited on both the inside and outside surface of a nozzle of diameter 0.3 mm. The oleophobicity was examined by comparing the discharge rates of a high-viscosity epoxy paste containing metal powders in coated and bare nozzles. The bare nozzle exhibited significant variations in discharge volume and frequently experienced clogging, while coated nozzles demonstrated consistent discharge rates and remained unclogged. These findings suggest that the proposed thin film coating has the potential to increase the lifespan and efficiency of ultra-fine nozzles in the automated micro-patterning industry.