Antifouling properties of chitosan coatings on plastic substrates

Abstract

In the current study, chitosan coatings were fabricated on plastic substrata and investigated for their antifouling activities. Scanning Electron Microscopy (SEM) and water contact angle measurement (WCA) of the fabricated chitosan films showed smooth and hydrophilic surface with WCA below 60°. Chitosan coating on plastic substrate showed 88% reduction in settlement of bryozoan Bugula neritina larvae compare to the control after 3 hours incubation in dark conditions with no larval mortality during the experiment. The antimicrobial activity of chitosan was evaluated by coating of plastic panels with the prepared chitosan solution and immersing the coated samples in seawater with controlled environmental conditions. Biofilms scraped from immersed chitosan coated panels showed no bacteria after 1 week immersion. After the second week of immersion, less than 1500 bacteria/mm2 was observed on the chitosan-coated panels compared to more than 105 bacteria/mm2 on uncoated ones. Thus, this study prove the efficiency of chitosan coatings against micro- and macro-fouling.