The objective of this Statement of Need (SON) was to close knowledge gaps associated with biological impacts on marine, aviation, and terrestrial coatings for Department of Defense (DoD) assets. The research should have focused on topics that relate biological presence to observed performance deterioration rates for a realistic characterization of the biological component on coating performance. Specific objectives of this SON included the following:
Successful proposals explored not only the biological components of this objective, but also provided insight to the changes in mechanical and physical properties of the coating and any chemical or biological byproduct interaction with coatings. Cross-disciplinary (and potentially multi-organization) teams were encouraged.
Proposals should have also included a plan to conduct an appropriately-scaled Sustainability Analysis.1
Program Managers, Warrant Holders, installations, and Warfighters across all services would benefit from an improved understanding of the relationship between biological activity and coating performance deterioration rates. Resulting studies will support the development of laboratory assays to guide future coating formulation design and testing and determine suitable preventive measures and material selection, which will enable more accurate prediction of coating cleaning, failure, and re-application rates. Tri-service environmental impacts include informing maintenance procedures (e.g., cleaning/re-coating), potentially reducing re-coating and cleaning frequencies, determining appropriate coating biocide/fungicide loading, and informing environmental regulations regarding biocide/fungicide toxicity, fate, and transport.
Organisms exist in every natural environment and have known impacts on coating performance and failure, such as marine bio-foulers, mold or fungi in humid terrestrial or aerial environments, or organisms involved with microbiologically influenced corrosion. These studies have shown that the organisms are capable of settlement and proliferation on nearly any surface, accelerate traditional corrosion and chemical degradation processes, and persist even after harsh physical or chemical cleanings that also cause coating material deterioration/loss. This can cause more frequent surface cleanings, prematurely fail protective coatings, compromise structural integrity, and influence coating re-application frequency and long-term adhesion.
Typical approaches to mitigate biological settlement include the use of biocides/fungicides with a loading/leach rate that will deter biological accrual. However, over the coating’s service life and under exposure to an array of environmental conditions, organism settlement still occurs. Eventually, the coating is cleaned either chemically or physically to remove organisms from the surface of the coating. Recent research has found that superficial cleanings of surfaces in both Air Force and Army applications do not fully address biological interaction with coatings. Organisms still remain on surfaces regardless of how recently they had been cleaned. This is also applicable to marine organisms. Underwater hull cleanings are required more frequently after the initial cleaning, and this phenomenon is still not well understood.
Fundamental knowledge gaps still exist within the area that prevent technology transition and long-term resolution of biological settlement and deterioration—in particular, the rate of bio-deterioration, either directly or through surface cleanings, and the successive impact on coating performance. Most previous research has focused on single organisms in unrealistic environments and there are no standard assays developed to provide a surrogate of performance deterioration rates due to biological activity. Resulting studies from this SON will guide future coating formulation design and testing, determine suitable preventive measures and material selection, and enable more accurate prediction of coating cleaning, failure, and re-application rates. Tri-service environmental impacts include informing maintenance procedures (e.g., cleaning/re-coating), potentially reducing re-coating and cleaning frequencies, determining appropriate coating biocide/fungicide loading, and informing environmental regulations regarding biocide/fungicide toxicity, fate, and transport.
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.