海洋环境腐蚀与生物污损重点实验室知识库

摘要

微生物腐蚀是造成海洋环境工程设施加速破坏的重要因素，而硫酸盐还原菌（SRB）是其中一种典型的腐蚀微生物。使用杀菌剂的传统化学防治法会破坏生态环境，增强细菌的耐药性。本研究针对这一问题，通过物理载药和化学载药等方法构建了三种不同类型的硫离子响应释放材料，检测了载药体系在不同硫离子浓度条件下的释放情况，揭示了载药材料的释放机制。主要结果如下：

（1）利用Cu-BTA能够形成络合物膜层的原理，将其作为封堵层，修饰到通过真空负载方式填充了杀菌剂分子（甲硝唑）的埃洛石纳米管端口处。研究了不同浓度铜离子溶液对载药体系的封堵效果以及载药体系在不同硫离子浓度条件下的释放情况。结果发现最佳的铜离子封孔浓度为10.24 g/L，载药体系能够实现对硫离子的响应释放，响应释放对应的最低硫离子浓度为3.2 mg/L。

（2）沿用了Cu-BTA能够形成络合物膜层的原理，用整体封堵的方式替换端口封堵的方式，用掺杂有Cu-BTA络合物的明胶溶液对负载杀菌剂（甲硝唑）的纳米管进行包覆处理。结果发现，能够对载药埃洛石纳米管实现有效封堵的纯明胶溶液的质量浓度为10 g/L，用明胶和Cu-BTA络合物对载药埃洛石纳米管进行混合包覆处理的最佳掺杂比例为1:1，测试结果还证明了经过包覆处理的载药埃洛石纳米管在硫离子条件下和酸性条件下能够实现响应释放，即具有双重响应性，对硫离子实现响应释放的最低浓度为32 mg/L。

（3）利用硫离子对金属离子参与形成配位键的破坏作用，改变之前物理载药的方式，以SBA-15分子筛作为载体材料，经过氨基修饰后，利用配位键的作用，分步嫁接不同金属离子和不同的杀菌剂，构建了“氨基-金属离子-杀菌剂”的载药体系。结果发现，结构中杀菌剂的释放情况有参与形成配位键的金属离子与硫离子结合形成硫化物的沉淀系数有关，即沉淀越容易形成，原先的配位键越容易被破坏，杀菌剂越容易释放出来，以铜离子为金属离子构建的载药体系的硫离子响应释放浓度最低为3.2 mg/L，万古霉素的释放量也最大，达到200 mg/L，最符合载药体系的构建要求，除此之外，实验也验证了杀菌剂分子结构中含有能与金属离子配位的官能团数量越多，杀菌剂分子与金属离子结合得越牢固。

Abstract

Microbial corrosion is an important factor causing accelerated damage to Marine environmental engineering facilities, and sulfate reducing bacteria (SRB) is one of the typical corrosion microorganisms. Traditional chemical control methods using fungicides can destroy the ecological environment and enhance bacterial resistance. To solve this problem, this study constructed three different types of sulfide-ion responsive release materials by means of physical drug loading and chemical drug loading, verified the release situation of the drug loading system under different concentration of sulfide-ion, and revealed the release mechanism of the drug loading material under the condition of sulfide-ion. The results are as follows:

(1) Based on the principle that Cu-BTA can form a complex film layer, it was modified as a blocking layer to the end of the halloysite nanotube filled with bactericide molecules (metronidazole) by vacuum loading. The blocking effect of copper ion solution with different concentration and the release of sulfide ions solution with different concentration were studied. The results showed that the best copper ions concentration was 10.24g /L, and the drug loading system could realize the response release of sulfide ion, and the corresponding minimum sulfide ions concentration was 3.2mg /L.

(2) Following the principle of the previous chapter, the port sealing method is replaced by the integral sealing method. The gelatin solution doped with Cu-BTA complex is used to coat the nanotubes loaded with bactericide (metronidazole). The results showed that the mass concentration of the pure gelatin solution which be able to take drug-loading nanotubes effectively blocked is 10 g/L; the optimal doping ratio of gelatin and Cu - BTA mixed complex coating for drug-loading halloysite is 1:1; the results also proved that drug-loading halloysite nanotubes can achieve the dual responsiveness under the condition of sulfide ions and acid ions, the minimum concentration of sulfide ions which realize the responsive release is 32 mg/L.

(3) Taking sulfide ions as the damage player for the coordination bond formed by the participation of metal ions, changing the way of physical loading before. Using the SBA - 15 molecular sieve as the carrier material, the coordination bond was built by grafting different metal ions and different fungicides step-by-step after the amino modified. Then the “amino-metal ion-microbicides" system was built. The results showed that the release of the bactericide is associated with sulfides precipitation coefficient formed by metal ions and sulfide ions, the easier precipitation formed, the easier original coordinate bond damaged, then fungicide was easier to release. With copper ions as metal ions, the lowest concentration of sulfide ions that caused the responsive release of drug-loading system is 3.2 mg/L, the quantity to vancomycin was up to 200 mg/L, it best fits the research needs. In addition, experiments had verified that the more coordination structure the fungicide molecule have, the more stable coordination bond they get.