The objective of this Statement of Need (SON) was to develop and scale environmentally-friendly textile coatings and/or modified fibers that provide both hydrophobic and hydrophilic properties to repel water, oils and other chemicals of concern without the use of per- and polyfluoroalkyl substances (PFAS). In order to replace or compete with current PFAS textile coatings, new technologies had to be:
- Omniphobic: Able to repel both hydrophilic and hydrophobic liquids, including water, oils, and toxic chemicals
- Scaleable: Able to scale manufacture to treat full textile rolls or garments
- Aqueous-based: Able to meet strict textile manufacturing limitations on flammable solvent use
- Material independent: Able to function on multiple textile types such as mixtures of natural, synthetic, stretch, and non-stretch fibers
- Durable: Able to provide resistance to UV light, temperature cycling and the same if not better resistance to laundering and abrasion as currently used Durable Water Repellent (DWR) technologies
Developed materials must have had no effect on the spectral reflectance values of the final fabric and fabrics must not present any dermal, inhalation, or other hazards or result in soil or water impacts. In addition, there had to be no detrimental effect on other coatings or functionalities, such as flame resistance or vector protection. Technologies should have been demonstrated on military relevant textiles and fabrics. Proposals should have also included a plan to conduct an appropriately-scaled Sustainability Analysis.1
Program managers, installations, and Warfighters across all military services would benefit from uninterrupted availability of PFAS-free high performance textiles for use in uniforms, shelters, tenting and miscellaneous fabrics.
Current PFAS-free treatments cannot provide the same level of performance and functionality as current PFAS-containing treatments required for military textiles and uniforms. PFAS encompass a variety of compounds with Cn-F2n+1 bonds and are commonly used in repellent textile coatings. The main PFAS chemicals used on textiles are polymers like polytetrafluoroethylene (PTFE) and short chain fluorinated polymers known as C6 or C4 chemistries. PFAS can be incorporated as an additive mixed into individual fibers or sprayed as a coating onto finished fabrics during manufacturing or after sale and are present in/on textiles in two forms: a non-polymerized compound that can be washed out or evaporated or as a molecule integrated into a fluorine free polymer network via covalent bonds. Non-polymerized PFAS can also be used as processing aids in the production of PFAS polymers and do not necessarily end up in the polymer but may be a byproduct. Long chains with carbon-fluorine bonds impart a high level of surface repellency against both water and oils by reducing surface energy.
End of life management is an important consideration when assessing the potential PFAS release into the environment. A study published in Environmental Science and Technology on the release of PFAS from carpet and clothing in model anaerobic landfill reactors indicates that carpet and clothing are most likely sources of PFAS in landfill leachate. PFAS that is polymerized and integrated into the textile could also be released into the environment when thermally decomposed.
The cost and time to meet the requirements of this SON were at the discretion of the proposer. Proposers submitting a Standard Proposal had to provide the rationale for this scale. The two options were as follows:
Standard Proposals: These proposals describe a complete research effort. The proposer should incorporate the appropriate time, schedule, and cost requirements to accomplish the scope of work proposed. SERDP projects normally run from two to five years in length and vary considerably in cost consistent with the scope of the effort. It is expected that most proposals will fall into this category.
Limited Scope Proposals: Proposers with innovative approaches to the SON that entail high technical risk or have minimal supporting data may submit a Limited Scope Proposal for funding up to $250,000 and approximately one year in duration. Such proposals may be eligible for follow-on funding if they result in a successful initial project. The objective of these proposals should be to acquire the data necessary to demonstrate proof-of-concept or reduction of risk that will lead to development of a future Standard Proposal. Proposers should submit Limited Scope Proposals in accordance with the SERDP Core Solicitation instructions and deadlines.