Polytetrafluoroethylene, better known by its brand name Teflon^®, is widely used as a coating material on many products, such as the coating on cookware to make it non-stick. However, polytetrafluoroethylene coatings are easily worn because of their poor adhesion to substrates, severely limiting their applications. This award supported fundamental research on a novel approach to significantly improve the wear resistance of polytetrafluoroethylene coatings through nanoscale interface engineering by incorporating polydopamine as an adhesive underlayer and polydopamine coated nanostructures in both the underlayer and the polytetrafluoroethylene coating. The team has developed fabrication processes for synthesizing various nanostructures with and without polydopamine coating and incorporated them in both the polydopamine underlayer and the polytetrafluoroethylene top layer. The team also evaluated the tribological performance of the resulting coatings, studied the coating adhesion strength, mechanical properties, and wear mechanisms. Furthermore, the team developed coatings with significantly improved wear resistance through the proposed nanoscale interface engineering.

This research has resulted in a fundamental understanding of the roles of the polydopamine underlayer and the polydopamine coated nanostructures in improving the wear resistance of the polytetrafluoroethylene coatings. The research results have been broadly disseminated through eleven journal publications, twenty-two conference presentations, three Ph.D. dissertations, one M.S. thesis, and three undergraduate honors theses. The research results provided valuable information to guide the rational design of wear-resistant thin polytetrafluoroethylene coatings for potential surface wetting and tribological applications. This new approach will allow wear-resistant thin polytetrafluoroethylene coatings to be deposited on any substrate materials without changing the underlining surface topography, thus providing potential solutions to retain a wide range of surface properties that rely on both surface topography and chemistry, including, but not limited to, self-cleaning, anti-fogging, anti-icing, anti-corrosion, anti-biofouling, drag reduction, and solid lubrication. These properties are critically important for applications in energy, aerospace, automotive, oil and gas, healthcare, and biomedical industries. Therefore, results from this research will benefit the U.S. economy and society. 

The project provided training opportunities for nine graduate students, seven undergraduate students, and two postdoctoral fellows in the emerging field of nanofabrication, surface engineering, coatings, and nanomechanics. Research findings have been integrated into a course on tribology, thereby exposing more students to cutting-edge research. The project team also developed nanotechnology presentations and delivered seminars to undergraduate students at various venues. The team supervised honors freshmen research for the Annual Honors Research Symposium, REU students in their research projects, and senior students in their honors thesis research. The undergraduate students that participated in this research acquired skills of literature search, analyzing and presenting experimental data, and writing technical reports and papers. These experiences improved their access to graduate schools and research careers.

Last Modified: 09/16/2021
Modified by: Min Zou