Designing Composite Coatings That Provide a Dual Defense against Fouling

Inspired by marine organisms that utilize spines and shape changes to prevent the biofouling of their surfaceS, we use computational modeling to design a gel-based composite coating that provides a two-pronged defense mechanism against the fouling of the underlying substrate. Using dissipative particle dynamics (DPD) Simulations, we construct a coating that encompasses rigid posts embedded in a thermoresponsive gel, which exhibits a lower critical solution temperature (LCST). When the gel is heated above its LCST, it collapses to expose the buried posts, which act as spines or spikes that prevent a solid particle from penetrating the layer: Moreover, we show that an imposed shear flow readily dislodges these particles and Washes them away from the coated substrate. As the system dissipates heat and cools, the LCST gel expands, and this dynamic morphological change can also be harnessed to dislodge the adsorbed particles. Thus, both the exposed posts and the swelling gels tan provide barriers to the penetration of particulates through the coating. In this manner, the coating provides a dual mechanism against the fouling of the substrate. This physical approach can be particularly beneficial because it does not require the release of any chemical substances that could have detrimental consequences to the environment.