Two professors at South China University of Technology have developed anti-fouling coatings from the ocean

Marine biodefacement is an international problem in the development and utilization of marine resources, and it is also one of the technical bottlenecks restricting the development of marine economy and maintaining the safety of sea defense. With people's increasing concern about marine environmental protection and the increasingly strict environmental regulations, defaced de-attached anti-fouling coatings have become the focus of research.Zhang Guangzhao and Ma Chunfeng of South China University of Technology have long worked on environmentally friendly marine anti-fouling materials. In addition to biodegradable polymer-based anti-fouling materials, we have been developing multi-functional silicone anti-fouling materials. In previous work, the team has designed a new class of silicone polyurium materials. Due to the difference of solubility parameters between silicone and polyceral, self-layering occurs in the process of film formation, thus forming a surface silicone PDMS rich layer, its low surface energy characteristics give the material excellent defacement desorption properties, and the strong hydrogen bond between the zirconium base and the substrate, giving the coating high force and adhesion. Marine experiments have shown that the material has good defaced release properties (Ind. Eng. Chem. Res., 2016, 55, 6671)。To improve the anti-fouling capability of silicone materials in static conditions, they have branched the organic small molecule anti-fouling agent triclosan malayamide to silicone-based polyurethanes, combining the low surface energy of the material with the anti-fouling properties of the anti-fouling agent molecules, thus achieving collaborative anti-fouling. The system does not release anti-fouling agents in the marine environment and therefore has little impact on the marine environment. In addition, the hydrogen bonds in polyurethane will effectively improve the material's performance and adhesion. Indoor and marine experiments have shown that the material has excellent resistance to bacteria, diatoms and barnacle larvae, while hydrophobic anti-fouling agents ensure the low surface energy properties of PDMS, and dual functionality gives the material excellent solid sea anti-fouling properties (ACS Appl. Mater. Interfaces, 2015, 7, 21030)。recently, they developed a re-coatable, self-healing silicone polyurium material through molecular design for problems such as silicone anti-fouling materials that are not easy to repair after breakage and poor static anti-fouling effects. In addition to having self-layering properties to retain the silicone's low surface energy and low elastic mould, the material exhibits excellent room temperature self-healing ability in seawater or air due to the strong hydrogen bonding of the zirconium-based units in the polymer connected between the flexible polymethylsiloxane chain segments(Figure 1, 2). In particular, while the material is non-degradable or hydrolytic in the marine environment, it can be used as a controlled release vector for environmentally friendly anti-fouling agents (DCOIT). The self-healing material and anti-fouling agent system can make THEIT linear controlled release, in the real sea has excellent static anti-fouling properties (Figure 3). At the same time, the system also has a good substrate adhesion performance, damage can be self-healing.
Figure 1. The self-healing process of silicone polysaccharids(a) the original sample; (b) Silicone polysaccharides/environmentally friendly anti-fouling agentsrelated work published in the Royal Society of Chemistry academic journal Journal of Materials Chemistry A (J. Mater. Chem. A, 2017, 5, 15855), and applied for a patent for an invention in China (201510733075.5; 201510735804.0)。 This series of work was obtained by the National Natural Science Foundation of China (No. 51573061; 51673074).
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