Assessing the extent of impact for UV self-emitting substrates
Abstract
Biofouling causes significant problems to marine vessels and equipment, including operational, functional, and financial hurdles. Biofilm formation in United States Navy Fleet costs between 180 and 260 million dollars per year. Early stages of biofilm begin to form during initial vessel submersion forming a slime and growing into complex biofouling communities of barnacles, sponges, and tunicates within days. Increased surface roughness increases hydraulic drag and fuel consumptions while corrosion causes significant irreparable damage to the vessel#s components. Biological growth and corrosion also damage oceanographic equipment and decreases the optical transparency of windows used for cameras and communication devices. -Current approaches for biofilm prevention on ships include use of (i) antifouling coatings such as biocide impregnated surfaces and (ii) fouling release coatings such as low adhesion surfaces. These methods are short lived, optically opaque and cause significant marine environmental repercussions. There is a need to develop new, transparent, environmentally benign, durable surface treatment to prevent biological fouling on windows of marine vessels. -UV for biofilm prevention is considered environmentally friendly and is being increasingly investigated due to its affordability and effectiveness in biofilm prevention. However, it is nearly impossible to distribute adequate light across the surface of interest such as a window. This is because of the steep decay of light as it moves away from the source due to light diffusion and attenuation. The ability to emit UV light evenly throughout a substrate would eliminate the barriers of using UV light for biofilm prevention on windows of marine vessels. Our approach is to glow UV light from the window itself to prevent biological attachment and growth. -The objective of the project is to improve on the technologies transparency and understand the extent of impact that UV self-emitting substrates can have on preventing biofilm formation on naval vessels. The objective will be accomplished through (1) Improving the method of surface modification while mathematically correlating optical acuity and visible light transmittance to UV emission, (2) Identifying the mechanism of biofilm inhibition, and (3) establishing an energy budget for UV emitting substrates. The expected operational performance improvements include (1) elimination of biofouling during long term vessel deployment while (2) maintaining optical transparency of the window. This performance improvement will eliminate the need for mechanical cleaning and enable longer missions without interruption. Findings from this study can assist in biofilm prevention in the entire ship#s hull. UV-C radiation would prevent biological growth in both stagnant and fast-moving environments. Because of the low flux needed for biofilm prevention and logarithmic light attenuation as it travels through a medium, UV-C glowing substrate would not damage surrounding marine life and environments. Last, any benefits of LED technology (ON/OFF cycle, adaptable flux and wavelength, ease of handling, long life) would be applicable to the UV-C emitting windows. Fundamental knowledge gained by this work includes understanding of the mechanisms in which UV radiation can prevent attachment and enhance detachment of biofilm on surfaces. -
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 15, 2023
- Source ID
- N000142312448
Entities
People
- Mariana Lopes
Organizations
- Office of Naval Research
- United States Navy
- University of Massachusetts