STTR Phase I: Aluminum Oxide Coatings as Fluorine-Free Hydrophobic Barriers for Paper

The broader/commercial impact of this Small Business Technology Transfer (STTR) Phase I project focuses on developing an alternative coating to per- and poly-fluoroalkyl substances. These chemicals feature strong carbon-fluorine bonds that are extremely persistent in the environment and have recently been shown to be hazardous to human health. These per- and polyfluoroalkyl compounds are widely used in industrial and personal use applications, including as water-proof coatings for paper, clothing, and packaging materials, as surfactants, and as flame-retardant and stain-repellent coatings, among many other applications. This project will provide a replacement coating that is inexpensive, non-hazardous, and can be applied to a wide range of surfaces, such as for textiles or paper products, which are the project’s initial market targets. The technological innovation is based on a fluorine-free, earth-abundant mineral coating, using a class of material that is novel for these types of applications. This project will lead to barrier coatings that are durable, highly water and oil repellent, and resistant to scratching and corrosion. The final product will serve as a drop-in replacement substitute for these coatings. Phase 1 will focus on providing necessary data on the durability and industrial feasibility of the technology. This Small Business Technology Transfer (STTR) Phase I project focuses on generating a viable chemical coating that can replace current fluorinated coatings. These fluorinated chemicals are used on a wide array of surfaces as anti-corrosion, anti-oxidation, waterproof, or other types of barrier coatings. This project’s proprietary mineral coatings are fluorine-free and prepared from earth-abundant, benign materials. This approach enables coating at ambient temperatures and pressures using a process that is not precedented for use on “soft” substrates like cotton or paper. This research will start by depositing films using solution processible techniques like spray or dip coating. These films will be investigated for their hydrophobicity by static goniometry and for their homogeneity and chemical compositions using surface analytical techniques such as scanning electron microscopy and x-ray photoelectron spectroscopy. These films will be investigated for their durability when exposed to environmental factors such as friction or washing, and the precursor’s compatibility with common additives found in competitive coatings will also be studied. It is expected that this project will result in a coating chemical and procedure that can generate functional, durable barrier films on any target substrate as a drop-in replacement for current per- and poly-fluoroalkyl containing products. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.