A team composed of researchers from University of Massachusetts Lowell, U.S. Army Combat Capabilities Development Command - Soldier Center (DEVCOM SC), Naval Research Lab (NRL), and Defense Centers for Public Health - Aberdeen (DCPH-A) will leverage previous work on per-and polyfluoroalkyl substances (PFAS)-free superhydrophobic coatings (Safer Alternatives for Readiness Program -DEVCOM) to develop sustainable PFAS-free superhydrophobic/omniphobic coatings. This project will help in understanding the fundamental relationship between polymeric binder composition, surface topography, and dual hierarchical particles and how they influence the omniphobicity of a PFAS-free coating. This work is anticipated to lead to the creation of environmentally friendly coatings that can repel both polar and non-polar liquids, and that can be used to create a scalable and sustainable coating methodology (spraying and/or dip coating) for multiple textile types.

Coatings will be tailored to provide omniphobic characteristics through manipulation of the coating composition (chemistry) and surface topography (dual hierarchical particles). More specifically, mixed fillers and novel binders will be used to tune and optimize the chemical and surface structure of these materials. Novel hierarchical reentrant micro/nanostructures will be designed to deliver the additional benefit of omniphobicity (be able to repel water, hydrocarbons [oil], and other liquid chemicals) to the existing PFAS-free superhydrophobic coating formulation. Additionally, the coating will leverage novel organosilane binders developed by NRL to ensure the coated textile will have excellent durability in terms of resistance to abrasion, laundering, and temperature cycling. The coating will initially be developed for application to military specific textiles, some of which are not traditionally used in the consumer market. A key characteristic lacking in the non-PFAS alternatives developed to date is durability, particularity in laundering, therefore the proper fiber adhesion will be critical to the success of the final coating formulation. The envisioned coating system can be easily scaled for dip or spray coating and use water or environmentally benign solvents, thereby reducing the environmental footprint and health risks. DCPH-A will evaluate the composition’s lifecycle, human health, and environmental impacts to ensure the coated textiles do not present hazards to human health and/or the environment.

The development of durable, PFAS-free, omniphobic repellent coatings that will meet the critical performance requirements needed for the protective clothing and equipment items of Warfighters. This work will provide a scientific understanding of the roles surface topography and polymer chemistry play in providing omniphobic coatings. This fundamental knowledge can be leveraged to develop safer, more durable textile coatings for use in DoD and other applications.