Biodegradable Poly(ester-anhydride) for New Antifouling Coating

Anti-barnacle biofouling coatings for the protection of marine vessels: synthesis and progress

Marine biofouling has gnawed both mobile and non-mobile marine structures since time immemorial, leading to the deterioration of designed operational capabilities as well as a loss of valuable economic revenues. Mitigation of biofouling has been the primary focus of researchers and scientists from across the globe to save billions of dollars wasted due to the biological fouling of marine structures. The availability of an appropriate environment along with favorable substrata initiates biofilm formation within a few minutes. The crucial element in establishing a gelatinous biofilm is the excreted metabolites of destructive nature and exopolymeric substances (EPSs). These help in securing as well as signaling numerous foulants to establish themselves on this substrate. The larvae of various benthic invertebrates adhere to these suitable surfaces and transform from juveniles to adult barnacles depending upon the environment. Despite biofouling being characteristically witnessed for a month or lengthier timeframe, the preliminary phases of the fouling process typically transpire on a much lesser timescale. A few natural and synthetic additives had demonstrated excellent non-toxic anti barnacle establishment capability; however, further development into commercial products is still far-fetched. This review collates the specific anti-barnacle coatings, emphasizing natural additives, their sources of extraction, general life cycle analysis, and concluding future perspectives of this niche product.

Engineering and Application Perspectives on Designing an Antimicrobial Surface

Infections, contaminations, and biofouling resulting from micro- and/or macro-organisms remained a prominent threat to the public health, food industry, and aqua-/marine-related applications. Considering environmental and drug resistance concerns as well as insufficient efficacy on biofilms associated with conventional disinfecting reagents, developing an antimicrobial surface potentially improved antimicrobial performance by directly working on the microbes surrounding the surface area. Here we provide an engineering perspective on the logic of choosing materials and strategies for designing antimicrobial surfaces, as well as an application perspective on their potential impacts. In particular, we analyze and discuss requirements and expectations for specific applications and provide insights on potential misconnection between the antimicrobial solution and its targeted applications. Given the high translational barrier for antimicrobial surfaces, future research would benefit from a comprehensive understanding of working mechanisms for potential materials/strategies, and challenges/requirements for a targeted application.

Highly Branched Copolymers with Degradable Bridges for Antifouling Coatings

The antifouling properties of traditional self-polishing marine antifouling coatings are mainly achieved based on their hydrolysis-sensitive side groups or the degradable polymer main chains. Here, we prepared a highly branched copolymer for self-polishing antifouling coatings, in which the primary polymer chains are bridged by degradable fragments (poly-ε-caprolactone, PCL). Owing to the partial or complete degradation of PCL fragments, the remaining coating on the surface can be broken down and eroded by seawater. Finally, the polymeric surface is self-polished and self-renewed. The designed highly branched copolymers were successfully prepared by reversible complexation mediated polymerization (RCMP), and their primary main chains had an M_n of approximately 3410 g·mol^-1. The hydrolytic degradation results showed that the degradation of the copolymer was controlled, and the degradation rate increased with increasing contents of degradable fragments. The algae settlement assay tests indicated that the copolymer itself has some antibiofouling ability. Moreover, the copolymer can serve as a controlled release matrix for antifoulant 4,5-dichloro-2-octylisothiazolone (DCOIT), and the release rate increases with the contents of degradable fragments. The marine field tests confirmed that these copolymer-based coatings exhibited excellent antibiofouling ability for more than 3 months. The current copolymer is derived from commonly used monomers and an easily conducted polymerization method. Hence, we believe this method may offer innovative insights into marine antifouling applications.

Dynamic surface antifouling: mechanism and systems

Marine biofouling is a global problem today. High efficiency and eco-friendly antifouling systems are in pressing need. In recent years, we have proposed the concept of dynamic surface antifouling (DSA). That is, a continuously changing surface can effectively prevent marine fouling organisms from landing and adhesion. Based on this strategy, we developed coatings with dynamic surfaces by using degradable polymers including polyester-polyurethane, modified polyester and poly(ester-co-acrylate). They exhibit tunable renewability, and excellent antifouling and mechanical performance. Moreover, the polymers can serve as carrier and controlled release systems of antifoulants so that they have long service life. This paper reviews the progress and trends in marine anti-biofouling, and presents the mechanism and systems of DSA.

Poly(ester)–poly(silyl methacrylate) copolymers: synthesis and hydrolytic degradation kinetics

Poly(MDO-silyl methacrylate) copolymers synthesized by RROP as promising degradable self-polishing copolymers (DSPC) for antifouling coatings.

Poly(dimethylsiloxane)-Based Polyurethane with Chemically Attached Antifoulants for Durable Marine Antibiofouling

Marine biofouling is a problem for marine industry and maritime activities. We have prepared polyurethane with poly(dimethylsiloxane) (PDMS) main chains and N-(2,4,6-trichlorophenyl) maleimide (TCM) pendant groups via a combination of a thiol-ene click reaction and a condensation reaction and studied its properties. The polymer has low surface energy and a high water contact angle. When TCM content in bulk is high enough, sufficient antifoulant groups can be exposed on the surface. Our study reveals that such polymeric surface can effectively inhibit the adhesion and colonization of marine organisms such as bacteria (Micrococcus luteus), diatom Navicula, and barnacle cyprids. Particularly, marine field tests demonstrate that the polymer has excellent antibiofouling performance in 110 days.