Highly efficient antifouling property based on self-generating hydrogel layer of polyacrylamide coatings

Synthesis and Properties of Self-Polishing Antifouling Coatings Based on BIT-Acrylate Resins

Painting antifouling coatings is one of the most important methods to prevent marine biofouling. Acrylic resin is widely used in marine antifouling because of its excellent stickiness, water resistance, and film-forming capabilities. At present, the widely used acrylate antifouling coatings require a high concentration of cuprous oxide as antifoulant. The release and accumulation of copper ions are the main factors affecting the marine environment. In this study, BIT–allyl methacrylate (BM) and zinc acrylate (ZM) were selected as functional monomers copolymerized with methyl methacrylate (MMA) and butyl acrylate (BA) to prepare a series of BIT acrylate antifouling resins. The inhibitory effects of all resins against marine bacteria (S. aureus, V. coralliilyticus, and V. parahaemolyticus), marine algae (Chlorella, I. galbana, and C. curvisetus), and barnacle larvae were studied. Moreover, marine field tests on the BIT modified resin in coastal waters were conducted. The results demonstrate that the grafted BIT–zinc acrylate resin not only exhibits excellent antifouling properties but also a significant self-polishing performance, providing a novel strategy to design a long-term antifouling resin with stable antifoulant release.

Preparation and Properties of Environmentally Friendly Marine Antifouling Coatings Based on a Collaborative Strategy

Long-term and green marine antifouling coatings are an important means to prolong the service life of ships and other marine instruments and equipment. To accomplish this, we prepared three new green and high-efficiency antifouling coatings containing phthalimide derivatives inspired by capsaicin (PDIC-AC) by using a collaborative strategy that incorporates self-polishing, fouling repelling, and antifouling properties. Static simulation tests confirmed that the zinc acrylate resin of the PDIC-AC has excellent self-polishing properties due to changes in the roughness, surface free energy, and mass loss. Antifouling tests demonstrated that both PDIC and PDIC-AC possess efficient antibacterial and anti-algal effects. Moreover, marine field tests showed that the PDIC-AC are highly antifouling for at least 9 months, and their antifouling effect is similar to that of an antifouling coating with chlorothalonil (CT-AC). The collaborative strategy in this study can be used to research and develop long-term environmentally friendly antifouling coatings.

Comparative analysis of two isocyanate-free urethane-based gels for antifouling applications

Amphiphilic gels consisting of acrylamide (AAM)/2-hydroxyethyl methacrylate (HEMA), hexafluorobutyl methacrylate (HFBMA) and non-isocyanate urethane dimethacrylate (NIUDMA) of varying molecular weights were compared. A three-level Taguchi analysis was performed using the amount of AAM/HEMA, HFBMA, NIUDMA and reaction time as dependent variables to determine the optimal formulation of the gels with maximized toughness and elastic modulus. The results were compared with commercial AF/FR Intersleek® coatings (IS 700, IS 900 and IS 1100SR) for their antifouling performance against a marine microalga (Navicula incerta), a marine bacterium (Cellulophaga lytica) and adult barnacles (Amphibalanus amphitrite). The toughness, elastic modulus and strain at break of the optimized AAM gels ranged from 3 to7 MPa, 25 to 72 MPa and 80% to 170%, respectively, whereas those of the optimized HEMA gels ranged from 1 to 3 MPa, 13 to 23 MPa and 76% to 160%, respectively. The gels, particularly AHN(E9) and HHN(E12), showed reductions of attachment compared with IS700 of up to 93% and 58%, respectively.

Tough amphiphilic antifouling coating based on acrylamide, fluoromethacrylate and non-isocyanate urethane dimethacrylate crosslinker

This study is focused on the development of tougher gels using combinations of acrylamide, fluoromethacrylate and a non-isocyanate urethane dimethacrylate (NIUDMA) crosslinker. The NIUDMA was tailored with 2, 3-epoxypropoxy propyl-polydimethylsiloxane segments E9 (MW = 0.36 kg mol^-1), E11 (MW = 0.5-0.6 kg mol^-1) and E12 (MW = 1-1.4 kg mol^-1). A 3 level Taguchi design was used to evaluate the role of each component of the ternary copolymer gel on the elastic modulus and toughness. The toughness ranged from 2.5-7 MJ m^-3 whereas the modulus ranged from 27-70 MPa. The formulations with the highest toughness and modulus were screened for their antifouling potential in biological assays against the microalga Navicula incerta and the bacterium Cellulophaga lytica. The E9 gels showed the best performance, achieving a 73% reduction in N. incerta cells and a 92% reduction in C. lytica biofilm remaining after water jetting treatments, when compared with the commercial Intersleek product IS700.