Polyurethane films modified with polyaniline-zinc oxide nanocomposites for biofouling mitigation

Eco-friendly antifouling coatings are considered to be superior alternatives over conventional biocidal agents that affect marine life adversely. Considering this fact, polyurethane (PU) films modified with a novel pigment [Polyaniline-Zinc oxide (PANI-ZnO) nanocomposites, 1-2% w/w] and phytic acid as a chelating dopant have been developed. The structure has been elucidated using Infrared Spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and the surface properties of the films were explored by using atomic force microscopy, contact angle measurements, and swelling ratios. PANI-ZnO nanocomposite particles conferred excellent chemical, mechanical and thermal properties to the PU films. The antifouling properties of the modified PU films were tested against marine bacteria (Gram negative: Vibrio harveyi and Gram positive: Bacillus licheniformis) both qualitatively and quantitatively (80 to 12% for V. harveyi and 75 to 20% for B. licheniformis). In-vitro studies displayed good antifouling performance of the modified PU-PANI-ZnO films. The present study offers a simple, moreover a passive (green) technology that allows restoration of submerged surfaces with minimal detrimental effect on marine flora and fauna.