Preparation and drag reduction performance of biomimetic coatings derived from gelatin-3,4-dihydroxyhydrocinnamic acid gels

The purpose of this study was to develop a biomimetic coating with good drag reduction characteristics. The inspiration for the concept can be attributed to the lubricating properties of fish mucus and the water-resistant bonding ability of mussels. In this study, gelatin-3,4-Dihydroxyhydrocinnamic acid (gelatin-DOPA) was synthesized by grafting catechol groups to gelatin using EDC/NHS chemistry. Gelatin-DOPA gels were then prepared by crosslinking gelatin-DOPA with Fe³⁺ ions and GTA. The concentration of catechol groups in the gelatin-DOPA was found to be 0.114 mmol/g using a UV spectrophotometer. The adhesion strength was measured by lap shear tests using a mechanical tester. The drag reduction rate was determined using a rheometer. The adhesive property of the gelatin-DOPA gels to a metal substrate increased to 5.35 MPa and a drag reduction performance of the biomimetic coating derived from gelatin-DOPA gels of 40 % was achieved. The results indicate that the biomimetic coating could be applied to underwater equipment, which has potential applications in marine fields.