A multilayered antifouling coating constructed using the synthesized capsaicin-mimicking N-(4-hydroxy-3-methoxy-benzyl) acrylamide

Abstract

Biofouling is a stepwise accumulation process involving participation of various molecules and marine organisms. To tackle this complex threat, development of efficient long-term antifouling coatings yet keeps elusive. Here we report a newly constructed coating with both antifouling activity and low surface energy. The special surface structure formed by silica spheres and fluorosilanes offers the coating superhydrophobicity. Capsaicin-mimicking N-(4-hydroxy-3-methoxy-benzyl)-acrylamide (HMBA) powder is synthesized via the Friedel-Crafts reaction and is used as the antifoulant additives in the coating. By the synergistic effect of surface superhydrophobicity and the dispersed antifoulant, the multilayered HMBA-silica coating effectively inhibits the adhesion of alginate, bovine serum albumin and Chlorella, their adhesion rate on the HS-3 coating is 11.9 %, 8.7 % and 3.3 % respectively. The HS-3 coating kills 96.6 % gram-negative bacteria E. coli and 99.9 % gram-positive bacteria S. aureus. Furthermore, the HMBA-silica coating significantly mitigates by its superhydrophobicity the corrosion of artificial seawater, its corrosion current density has decreased by 4 orders of magnitude compared to bare 316 L plate. In a 90 days real seawater immersion experiment, the coating shows excellent anti-fouling and anti-corrosion properties. The fabrication route of the HMBA-silica coating using the synthesized broad-spectrum antifoulant HMBA and hydrophobic silica would give insight into developing new antifouling materials for marine applications.