NH2-ZIF-7 MOFs负载羧基化苯并异噻唑啉酮防污剂的制备和抗菌防污性能研究

目的 开发长效缓释且具有生物相容的绿色环保防污剂，消除防污剂在涂层中初期“爆释”、后期无法释放的弊端，实现新型缓释剂长效防污的功效。方法 通过简单的浸渍法负载防污剂分子，实现有效且缓慢释放;通过SEM、TEM观察负载前后纳米粒子的形貌;通过FT-IR、XRD、TGA、XPS、BET探究客体分子与纳米容器间的耦合作用，利用UV-Vis测试其释放性能;通过抑菌圈、平板菌落计数法、浊度法测试其抑菌性能;通过激光共聚焦观察涂层表面防细菌/藻类贴附性能。结果 氨基ZIF-7(NH2-ZIF-7)成功负载羧基化1,2-苯并异噻唑啉-3-酮(BIT-COOH)，实现了有效封装和稳定释放，并且金属有机框架材料负载后(NH2-ZIF-7@BIT-COOH)，革兰氏阴性菌(E.coli)和革兰氏阳性菌(S.aureus)的抑菌圈直径分别提高至(21.7±0.2)和(21.7±0.3)mm。进一步利用激光共聚焦观察涂层表面的细菌/藻类贴附情况，表明添加质量分数4%NH2-ZIF-7@BIT-COOH的混合树脂涂层具有优异的防细菌/藻类贴附性能。结论 利用NH2-ZIF-7封装BIT-COOH防污剂，可有效捕获、稳定释放并具有优异的抗菌性能，另外在丙烯酸树脂涂层中加入NH2-ZIF-7@BIT-COOH新型缓释防污剂能够有效抑制细菌/海藻的贴附，为新型缓释长效广谱低毒的防污剂开发提供了新的思路。

Preparation and Antibacterial and Antifouling Properties of Carboxylated Benzisothiazolinone Biocide Loaded NH2-ZIF-7 MOFs

Marine biofouling, caused by attachment of organism to solid surface, is a worldwide issue that affects the exploitation of marine resources. The use of organic coatings containing various antifoulants is currently the most economical, convenient and effective strategy to solve this problem. In view of the current antifouling agents, the overuse of antifouling agents in the coating at the early stage leads to explosive release, while the release rate stabilizes in the middle and late stages, so its concentration is not sufficient to inhibit the growth of fouling substances. Therefore, how to reduce the amount of antifouling agent used and effectively control the release rate of antifouling agents while ensuring antifouling efficiency is the main research direction in the field of antifouling coatings. In this study, an amine functionalized ZIF-7 (NH2-ZIF-7) metal-organic framework nanocontainers with mesoporous structure were successfully prepared, and a liquid-phase diffusion method was used to effectively capture carboxylated 1,2-Benzoisothiazolin-3-one (BIT-COOH). The morphology of nanoparticles before and after encapsulation of antifouling agent was characterized by SEM and TEM. The successful loading guest molecules in nanocontainers were investigated by FT-IR, XRD, TGA, XPS and their nitrogen adsorption-desorption curve, and the release performance was tested by UV-Vis. The bacteriostatic activity was tested by zone of inhibition method, plate colony counting method and turbidity method. The anti-bacterial/algae adhesion performance of the coating surface was observed by the bio-laser confocal microscope. The results showed that the NH2-ZIF-7 successfully wrapped the BIT-COOH, achieving effective capture and stable release. The inhibition performance against Gram-negative bacteria (E. coli) and Gram-positive bacteria (S.aureus) was significantly higher than that of NH2-ZIF-7 carriers, and the diameter of inhibition zone increased to (21.7± 0.2) and (21.7±0.3) mm, respectively. Further, the antibacterial performance of the acrylic hybrid resin coating loaded with LIVE/DEAD BacLightbacterial viability test kit was used to observe the antibacterial adhesion performance of the acrylic hybrid resin coating surface containing metal organic framework material loading (NH2-ZIF-7@BIT-COOH), showing that the antibacterial adhesion performance of the mixed resin coating with mass fraction 4% (NH2-ZIF-7@BIT-COOH) was significantly better than that of the blank control coating without antifouling agent. In addition, the resin coating with mass fraction 4% (NH2-ZIF-7@BIT-COOH) also exhibited the better antifouling performance. The adhesion rates of Chlorella, Phaeodactylum tricornutum and Isochrysis galbana on the coating surface of the blank group were 11.31%, 58.16% and 49.99%, respectively, while the adhesion area of algae on the surface of the mixed resin coating with mass fraction 4% (NH2-ZIF-7@BIT-COOH) was reduced to 0.06%, 0.05% and 0.05%, respectively. The NH2-ZIF-7 can effectively capture BIT-COOH and release stably, and has excellent antibacterial performance. In addition, the experiment of preventing bacteria/algae adhesion proves that the mixed resin coating provides long-term protection for the marine antifouling coating with anti-biological adhesion through the effective release of the antifouling agent.