Synthesis of Amphiphilic Acrylate Boron Fluorinated Polymers with Antifouling Behavior

Surface hydrolysis-anchored eugenol self-polishing marine antifouling coating

Traditional self-polishing antifouling coatings kill surface organisms by releasing toxic substances, which are damaging to the ecosystem. As a natural antimicrobial substance, eugenol is environmentally friendly and has been proven by different research teams to be effective in enhancing the anti-fouling effect of coatings in the real sea. While in these previous research works, the eugenol was released directly into the seawater thus cannot further serve as surface antifouling effect, leading to a limited antifouling effect of the coating. In this work, the quaternary ammonium component was introduced into the butyl ester-based resin - poly (eugenol methacrylate - acryloyloxyethyltrimethyl ammonium chloride - hexafluorobutyl methacrylate - methyl methacrylate - butyl methacrylate - ethylene glycol methyl ether acrylate) (EMQFP) coating for the first time by simple one-step free radical polymerization method. On the one hand, the eugenol produced by hydrolysis is anchored to the quaternary ammonium on the coating surface for a period of time due to the cationic-π interaction, instead of being released into seawater immediately after hydrolysis, thus increasing the utilization rate of eugenol; on the other hand, the negatively charged carboxylate groups generated after hydrolysis in the coating are mutually attracted to quaternary ammonium through electrostatic effect, so the resin chain segment conformation on the coating surface adjusted to produce zwitterionic-like structure, and the hydration of zwitterionic inhibits primary fouling adhesion.

Constructing three-dimensional network C, O Co-doped nitrogen-deficient carbon nitride regulated by acrylic fluoroboron overall marine antifouling

To deal with unwanted biofouling adsorption, which impacts the economy and the environment, significant research has been devoted to composite systems involving a photocatalyst combined with self-renewal resin to provide synergistic antifouling. Here, photocatalyst based on three-dimensional (3D) network of carbon-oxygen-doped nitrogen-deficient carbon nitride and acrylic fluoroboron polymer as a system was successfully synthesized. 3D networks carbon nitride with carbon-oxygen dopants and nitrogen defects were prepared as skeletons, which effectively support and regulate the hydrolysis rate of the polymer. These composite systems exhibits excellent diatom anti-adhesion performance and high antibacterial rates for Escherichia coli and Staphylococcus aureus of up to 91.87% and 88.52%, respectively. In addition, self-cleaning function of the composite system are proved by and higher efficiency of chemical oxygen demand (COD) removal owing to efficient charge-carrier separation and transfer within the 3D network carbon nitride network. The great potential applications of this strategy demonstrated in marine engineering in the future.

Amphiphilic Zwitterionic Acrylate/Methacrylate Copolymers for Marine Fouling-Release Coatings

Methacrylate and acrylate monomers are popular building blocks for antifouling (AF) and fouling-release (FR) coatings to counteract marine biofouling. They are used in various combinations and often combined into amphiphilic materials. This study investigated the FR properties of amphiphilic ethylene glycol dicyclopentenyl ether acrylate (DCPEA) and the corresponding methacrylate (DCPEMA) blended with 5 wt % zwitterionic carboxybetaine acrylate (CBA) and the corresponding methacrylate (CBMA). A series of (co)polymers with different acrylate/methacrylate compositions were synthesized and tested against the attachment of the diatom Navicula perminuta and in short-term dynamic field exposure experiments. The more hydrophobic methacrylate DCPEMA homopolymer outperformed its acrylate counterpart DCPEA. Incorporated zwitterionic functionality of both CBMA and CBA imparted ultralow fouling capability in the amphiphilic polymers toward diatom attachment, whereas in the real ocean environment, only the employment of CBMA reduced marine biofouling. Moreover, it was observed that CBA-containing coatings showed different surface morphologies and roughnesses compared to the CBMA analogues. Particularly, a high impact was found when acrylic CBA was mixed with methacrylic DCPEMA. While the wettability of the coatings was comparable, investigated methacrylates in general exhibited superior fouling resistance compared to the acrylates.

Photocatalytic antifouling coating based on carbon nitride with dynamic acrylate boron fluorinated polymers

Study on the preparation and properties of an environmentally friendly photocatalytic antifouling coating.

Natural Product Inspired Environmentally Friendly Strategy Based on Dopamine Chemistry toward Sustainable Marine Antifouling

The combination of natural active antifouling composition and intelligent coatings has been regarded as a prospective approach to avoid marine biofouling. However, the relatively complex coating structure and the excessive rapid release of antifoulants maintain unresolved issues in their practical application. In this work, a novel environmentally friendly natural antifoulant (Stellera chamaejasme, SC) encapsulated in the polydopamine (PDA) microcapsule (SC@PDA) is prepared by emulsion interfacial polymerization and blended with the acrylate polymer to prepare a sustainable antifouling coating. Herein, the PDA shell acting as an "intelligent capsule" ensures the controlled release of the antifoulant SC, and the corresponding SC loading amount could be high up to 75.40%. As a model antifoulant, the impact of SC on the adsorption activity of the protein bovine serum albumin (BSA) is studied, as well as the settlement of presentative fouling communities (diatom Navicula sp. and red algae Porphyridium sp.) on the constructed coating. The experimental results demonstrate that the natural product SC integrated eco-friendly antifouling coating occupies the superior capacity of impeding the adsorption of both protein BSA and algae. Such antifoulant (SC) integrating with controlled release character is a great advance in terms of marine antifouling applications. It is, therefore, expected that this innovation will provide guiding significance for developing the next generation of antifouling techniques, especially in the field of marine antifouling.

The Effect of Poly(ethylene glycol) (PEG) Length on the Wettability and Surface Chemistry of PEG-Fluoroalkyl-Modified Polystyrene Diblock Copolymers and Their Two-Layer Films with Elastomer Matrix

Diblock copolymers composed of a polystyrene first block and a PEG-fluoroalkyl chain-modified polystyrene second block were synthesized by controlled atom transfer radical polymerization (ATRP), starting from the same polystyrene macroinitiator. The wettability of the polymer film surfaces was investigated by measurements of static and dynamic contact angles. An increase in advancing water contact angle was evident for all the films after immersion in water for short times (10 and 1000 s), consistent with an unusual contraphilic switch of the PEG-fluoroalkyl side chains. Such a contraphilic response also accounted for the retained wettability of the polymer films upon prolonged contact with water, without an anticipated increase in the hydrophilic character. The copolymers were then used as surface-active modifiers of elastomer poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)-based two-layer films. The elastomeric behavior of the films was varied by using SEBS matrices with different amounts of polystyrene. Whereas the mechanical properties strictly resembled those of the nature of the SEBS matrix, the surface properties were imposed by the additive. The contraphilic switch of the PEG-fluoroalkyl side chains resulted in an exceptionally high enrichment in fluorine of the film surface after immersion in water for seven days.

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.