MECHANORESPONSIVE ANTI-FOULING POLYMERS BASED ON UNVEILING FUNCTIONAL CROSS-LINKS
Abstract
The adhesion of sea organisms to the hull of a vessel, termed marine biofouling, drasticallyincreases the drag force on the vessel."" Biofouling costs the Navy approximately $200 millionannually. Since biofouling organisms are diverse in size, biochemistry, and ad""hesion mechanism,the only hull coatings to date that have been successful at preventing most of the organisms fromattaching are th"ose that are broadly toxic and pollute the water. We are proposing an innovativeand non-toxic approach to prevent biofouling - a stimuli responsive hull coating that naturallyrepels many organisms and will adapt to any organism that succeeds in attaching by becominginhospitable to that organism. This coating is based on polymers composed of hydrophobicbackbones and hydrophilic side chains." In the default state, the hydrophilic side chains are hiddenas cross-links and the polymer is hydrophobic. When force is applied b""y an attaching organism,the cross-links are broken, thereby revealing a hydrophilic material. We will take a combinedsynthetic, ex""perimental, and constitutive modeling approach to design this material. The synthesiswill be performed with monomers and processes" that are industrially common and environmentallyfriendly. These monomers are largely interchangeable providing a wide range of options fortailoring the material performance. The constitutive modeling will be based on previouslydeveloped multiscale approaches f"or mechanochemically active polymers. The model predictionswill be used to guide the choice of polymer backbone chemistry, molecula""r weight, side chainlength, and percent cross-linking. Experiments on the coatings will be conducted to determine themechanical pr""operties, the hydrophilicity of the surface, and the coupling between the two. Theseexperimental results will be used to assess the" synthesized materials and validate and improve thepredictive capabilities of the constitutive model. Towards the later stages of the project theantifouling performance of the coating will be assessed against exposure to several model foulingspecies that captur"e the range of species encountered in marine environments. If successful, thisstimuli responsive polymer will be used as a top coat"" for marine vessels, cutting down fuelconsumption, increasing top speed, and reducing maintenance requirements. From a broadermate""rials development perspective, the polymer design concept (and associated material model)of inducing a material property change by"" mechanically breaking weak reversible cross-links willbe useful for formulating options for other adaptive material applications,"" such as sensing andcamouflage, based on mechanical stimuli.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 29, 2017
- Source ID
- N000141712989
Entities
People
- Meredith N Silberstein
Organizations
- Cornell University
- Office of Naval Research
- United States Navy