海洋环境腐蚀与生物污损重点实验室知识库

微生物腐蚀（Microbiologically influenced corrosion, MIC）对海洋工程设施造成了巨大安全隐患和经济损失。涂层防护是解决MIC问题的有效方式，为进一步改善涂层防护性能，可在其中添加一些溶出型防污剂，在涂层服役过程中，伴随着防污剂不断渗出，对其表面附近的微生物具有一定忌避或杀灭作用，从而抑制微生物的粘附及对材料的腐蚀进程。然而，直接在涂层中加入防污剂会导致一些负面效应，例如防污剂不可控释放、涂层性能退化和防污剂抑制能力丧失，而且过量释放的防污剂会使微生物产生耐药性以及污染环境。因此，设计与开发智能防护涂层变得极为迫切。智能涂层能响应环境的变化，继而释放负载的防污剂，有效避免了向传统涂层中直接添加防污剂所面临的问题。

本文基于模式产酸菌（Acid producing bacteria, APB）和典型海洋腐蚀微生物硫酸盐还原菌（Sulfate reducing bacteria, SRB）的代谢特性，从绿色原料、合理设计、应用前景的角度出发，首次开发了包括pH响应型聚合物膜层、硫离子（S^2-）响应型金属-多酚膜层、高敏感S^2-响应型纳米容器基涂层及高稳定S^2-响应型纳米容器基涂层在内的四种具有pH/S^2-响应释放杀菌剂性能的智能涂层，通过对APB/SRB腐蚀发生时代谢的酸/硫化物信号做出响应，实现了负载杀菌剂的可控释放；通过响应释放效率评估、释放前后成分、形貌分析，解析了杀菌剂响应释放机制；通过涂层抑菌性能及微生物腐蚀防护性能评价，阐明了智能涂层微生物腐蚀防护机制，这些研究为海洋微生物腐蚀防护提供了新思路。具体研究内容及结论如下所述：

（1）采用单宁酸（Tannic acid, TA）与壳聚糖（Chitosan, CH）为主要原料，通过静电层层自组装法合成了包埋杀菌剂三氯生（Triclosan, TCS）的核-壳结构纳米胶囊（TCS@CTAB/TA/CH），采用共价键层层自组装法，交替沉积TCS@CTAB/TA/CH纳米胶囊和右旋糖酐醛（Dextran aldehyde, DA），制备得到聚合物多层膜(DA-TCS@CTAB/TA/CH)_n。该多层膜可以对pH变化作出响应，控制释放包埋TCS分子，在pH=6时对大肠杆菌在24 h内的杀灭率达到99.62 %，表现出优异的抗菌及抗粘附性能，为用于产酸菌腐蚀防护提供了可能。

（2）基于SRB的代谢特性，以天然聚多酚TA和金属铁离子（Fe^Ⅲ）为主要原料，在金属铝表面构筑了S^2-响应型金属-多酚超分子膜层，利用TA- Fe^Ⅲ络合物对S^2-的敏感性，实现负载杀菌剂TCS的可控释放。当Na₂S浓度为15 mM时，在6000 s内释放了60%的TCS，甚至较低的Na₂S浓度（10 mM）也能够刺激5 %的TCS释放。由此制备的膜层在无SRB粘附时保持稳定，当遭受SRB粘附并造成腐蚀时，受代谢的硫化物信号刺激释放防污剂，抑制微生物在材料表面附着过程，从源头上抑制了微生物腐蚀行为发生。

（3）利用2-甲基咪唑锌盐ZIF-8作为自牺牲模板制备空心介孔二氧化硅纳米粒子（Hollow mesoporous silica nanoparticles, HMSNs），吸附杀菌剂甲硝唑（Metronidazole, MNZ）后再将ZIF-8作为纳米阀门接枝在HMSNs表面，制备了高敏感S^2-响应型纳米容器（MNZ-HMSNs@ZIF-8）。利用ZIF-8对S^2-的敏感性来控制HMSNs孔道中杀菌剂释放，当Na₂S浓度为0.04 mM时即能在12000 s内实现49%的释放，进一步提升了S²⁻响应性能。将纳米容器与商用水性醇酸树脂共混后沉积得到智能涂层，由于赋予了智能涂层响应释放杀菌剂能力，智能涂层在SRB介质中挂片14天后表现出优异的抗细菌粘附性能，结合电化学实验表明智能涂层具有最佳的SRB腐蚀防护性能。

（4）利用一步法直接将商用防污剂4,5-二氯-N-辛基-4-异噻唑啉-3-酮（DCOIT）封装进ZIF-8骨架结构中，从分子尺度上避免了防污剂泄露，制备了高稳定S^2-响应型纳米容器（DCOIT@ZIF-8）。DCOIT@ZIF-8在长达21天时间内几乎没有泄露防污剂，在8 mM Na₂S条件下可释放74.01%的防污剂。高稳定性纳米容器的存在延长了复合涂层的服役期限，在30天内可以实现优异的抗粘附性能及微生物腐蚀防护性能。

Microbiologically influenced corrosion (MIC) has caused huge safety hazards and economic losses to marine engineering facilities. Coating protection is an effective way to solve MIC risk. Some antifouling agents can be added to coating to further improve the protective performance. In the service process of coating, it will be accompanied by the continuous release of antifouling agent, which can repel or kill microorganisms near the coating surface, inhibit bacterial adhesion and corrosion on metal materials. However, the direct addition of antifouling agent to coating will cause negative effect, such as uncontrollable release of agent, degradation of coating performance and loss of antifouling ability. Furthermore, the excessive release of antifoulant will cause anti-microbial resistance and environmental pollution. Therefore, the design and development of intelligent protective coatings have become extremely urgent. The intelligent coating can respond to environmental stimuli and then release the loaded antifouling agent, effectively avoiding the problems caused by direct addition of antifouling agents to traditional coatings.

Based on the metabolic characteristics of acid-producing bacteria (APB) and typical marine corrosive microorganism sulfate-reducing bacteria (SRB). Four coatings with pH/sulfide ion (S^2-) responsive release of antibacterial agents were developed from the perspectives of green raw material, reasonable design and application prospect, including pH-responsive polymer film, S^2--responsive metal-polyphenol film, high-sensitive S^2--responsive nanocontainers-based coating and high-stable S^2--responsive nanocontainers-based coating. The intelligent coatings realized controllable release of loaded antibacterial agent by responding to the acid/sulfide signal metabolized by APB/SRB. The responsive release mechanism of bactericides was illuminated through the release efficiency evaluation, composition and morphology analyses before and after the release. The microbiological corrosion protection mechanism of intelligent coating was also clarified by the performance evaluation of antibacterial and microbial corrosion protection. These studies provide innovative ideas for marine microbial corrosion protection. The specific research contents and conclusions are as follows:

(1) Using tannic acid (TA) and chitosan (CH) as the raw materials, the core-shell nanocapsules (TCS@CTAB/TA/CH) encapsulated with the biocide triclosan (TCS) were synthesized via the electrostatic layer-by-layer self-assembly method. The polymer multilayer film (DA-TCS@CTAB/TA/CH)_n was fabricated by alternately depositing TCS@CTAB/TA/CH nanocapsules and dextran aldehyde (DA) using the covalent layer-by-layer self-assembly method. The film can respond to pH changes and release the loaded TCS molecules. The film reached the antibacterial rate of 99.62% against E. coli within 24 hours at pH 6, showing excellent antibacterial and anti-adhesive properties. It provided a possibility for APB corrosion protection.

(2) Based on the metabolic characteristic of SRB, S^2--responsive metal-polyphenol supramolecular film was constructed on the aluminum surface using natural polyphenol tannic acid (TA) and iron ions (Fe^Ⅲ) as the raw materials. Due to the sensitivity of TA-Fe^Ⅲ complex to S^2-, the controlled release of loaded antibacterial agent TCS was realized. 60% of TCS was released within 6000 s when the Na₂S was 15 mM, and even a lower Na₂S concentration (10 mM) can stimulate 5% of TCS to release. The film remains stable when there is no SRB adhesion. When it suffers from SRB adhesion and corrosion, it is stimulated by the metabolic sulfide to release the antibacterial agent, which inhibits the adhesion process of microorganisms on material surface, and subsequently suppress the MIC behavior.

(3) The hollow mesoporous silica nanoparticles (HMSNs) were prepared using ZIF-8 as self-sacrificing template. Then, the high-sensitive S^2--responsive nanocontainers (MNZ-HMSNs@ZIF-8) were prepared by installation of ZIF-8 nanovalves on surface of HMSNs after the adsorption of bactericide metronidazole (MNZ). Taking advantage of the sensitivity of ZIF-8 to S^2-, the bactericides in the HMSNs can be control to release. When the concentration of Na₂S is 0.04 mM, 49% of release can be achieved within 12000 s, which further improves the response to SRB. The intelligent coating was prepared by deposition of commercial water-based alkyd resin mixed with the nanocontainers. Due to the coating with ability of responsive release of biocides, the smart coating exhibited excellent bacterial adhesion resistance after being suspended in SRB medium for 14 days. Combined with electrochemical results, the intelligent coating possessed the best SRB corrosion protection performance.

(4) The high-stable S^2--responsive nanocontainers (DCOIT@ZIF-8) were prepared via direct encapsulation of commercial antifouling agent 4,5-dichloro-2-octyl-4-isothiazolin-3-one (DCOIT) into the ZIF-8 framework structure using one-step method, which avoiding the leakage of agents on the molecular scale. Almost no leakage of antifouling agent in 21 days from the nanocontainers, and 74.01% of antifouling agent can be released under the condition of 8 mM Na₂S. The existence of stable nanocontainers extends service life of the composite coating, which achieving excellent adhesion resistance and microbiological corrosion protection performance within 30 days.

第一章 绪论... 1

1.1 海洋微生物腐蚀... 1

1.1.1 产酸菌腐蚀... 2

1.1.2 硫酸盐还原菌腐蚀... 3

1.2 海洋微生物腐蚀防护技术... 7

1.2.1 物理法... 7

1.2.2 化学法... 8

1.2.3 生物法... 8

1.2.4 阴极保护法... 9

1.2.5 涂层防护法... 9

1.3 环境刺激响应型智能抗菌表面研究概况... 9

1.3.1 pH响应型智能抗菌表面... 10

1.3.2 酶响应型智能抗菌表面... 12

1.3.3 温度响应型智能抗菌表面... 13

1.3.4 光电响应型智能抗菌表面... 14

1.3.5 离子响应型智能抗菌表面... 15

1.4 环境刺激响应型智能防腐涂层研究概况... 16

1.4.1 pH响应型智能防腐涂层... 16

1.4.2 腐蚀电位响应型智能防腐涂层... 19

1.4.3 腐蚀性离子响应型智能防腐涂层... 20

1.4.4 光响应型智能防腐涂层... 21

1.4.5 磁场响应型智能防腐涂层... 23

1.5 选题意义与研究内容... 23

1.5.1 选题意义... 24

1.5.2 研究内容... 25

第二章 pH响应型聚合物多层膜制备及其抑菌性能研究... 27

2.1 引言... 27

2.2 实验部分... 27

2.2.1 实验材料、试剂... 27

2.2.2 纳米胶囊制备... 27

2.2.3 聚合物多层膜制备... 28

2.2.4 样品表征... 29

2.2.5 纳米胶囊和聚合物多层膜pH响应释放TCS性能测试... 29

2.2.6 聚合物多层膜抑菌性能测试... 30

2.2.7 聚合物多层膜自抛光性能测试... 31

2.3 结果与讨论... 31

2.3.1 纳米胶囊的表征... 31

2.3.2 纳米胶囊pH响应释放TCS性能... 33

2.3.3 聚合物多层膜的表征... 35

2.3.4 聚合物多层膜短期抑菌性能... 38

2.3.5 聚合物多层膜长期抑菌性能... 41

2.3.6 聚合物多层膜自抛光性能... 42

2.4 本章小结... 45

第三章 硫离子响应型金属-多酚膜层制备及其硫酸盐还原菌腐蚀防护性能研究    46

3.1 引言... 46

3.2 实验部分... 47

3.2.1 实验材料、试剂... 47

3.2.2 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层的制备... 47

3.2.3 样品表征... 48

3.2.4 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层S^2-/SRB响应释放TCS性能测试... 48

3.2.5 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层抑制SRB附着性能评价... 48

3.2.6 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层对铝的SRB腐蚀防护性能评价... 49

3.3 结果与讨论... 50

3.3.1 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层表征... 50

3.3.2 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层S^2-/SRB响应释放TCS性能... 54

3.3.3 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层抑制SRB附着性能... 56

3.3.4 TCS@CTAB-(TA-Fe^Ⅲ)₂₀膜层对铝的SRB腐蚀防护性能... 59

3.4 本章小结... 65

第四章 高敏感硫离子响应型纳米容器基涂层制备及其硫酸盐还原菌腐蚀防护性能研究    66

4.1 引言... 66

4.2 实验部分... 67

4.2.1 实验材料、试剂... 67

4.2.2 MNZ-HMSHs@ZIF-8纳米容器制备... 68

4.2.3 MNZ-HMSHs@ZIF-8纳米容器S^2-响应释放MNZ性能测试... 69

4.2.4 掺杂纳米容器的智能涂层制备... 69

4.2.5 SRB细菌培养... 70

4.2.6 MNZ-HMSNs@ZIF-8纳米容器抑菌性能评价... 70

4.2.7 智能涂层抑制SRB附着性能评价... 70

4.2.8 智能涂层对碳钢SRB腐蚀防护性能评价... 71

4.2.9 样品表征... 71

4.3 结果与讨论... 71

4.3.1 MNZ-HMSNs@ZIF纳米容器表征... 71

4.3.2 MNZ-HMSNs@ZIF-8纳米容器S²⁻响应释放MNZ性能和机理... 75

4.3.3 MNZ-HMSNs@ZIF-8纳米容器抑菌性能... 79

4.3.4 智能涂层表征... 80

4.3.5 智能涂层抑制SRB附着性能... 81

4.3.6 智能涂层对碳钢SRB腐蚀防护性能... 83

4.3.7 智能涂层对碳钢SRB腐蚀防护机制... 88

4.4 本章小结... 89

第五章 高稳定硫离子响应型纳米容器基涂层制备及其硫酸盐还原菌腐蚀防护性能研究    91

5.1 引言... 91

5.2 实验部分... 92

5.2.1 实验材料、试剂... 92

5.2.2 DCOIT@ZIF-8纳米容器制备... 92

5.2.3 DCOIT标准曲线测量... 92

5.2.4 DCOIT@ZIF-8纳米容器中DCOIT负载率测量... 92

5.2.5 DCOIT@ZIF-8纳米容器S^2-响应释放DCOIT性能测试... 93

5.2.6 智能防污/防腐多功能涂层制备... 93

5.2.7 SRB细菌培养... 94

5.2.8 DCOIT@ZIF-8纳米容器抑菌性能评... 94

5.2.9 智能抗菌/防腐多功能涂层抑制SRB附着性能评价... 94

5.2.10 智能抗菌/防腐多功能涂层对碳钢SRB腐蚀防护性能评价... 94

5.2.11 样品表征... 94

5.3 结果与讨论... 94

5.3.1 DCOIT@ZIF-8纳米容器表征... 94

5.3.2 DCOIT标准曲线... 96

5.3.3 DCOIT@ZIF-8纳米容器中DCOIT负载率... 97

5.3.4 DCOIT@ZIF-8纳米容器S^2-响应释放DCOIT性能... 98

5.3.5 DCOIT@ZIF-8纳米容器抑菌性能... 103

5.3.6 智能抗菌/防腐多功能涂层抑制SRB附着性能... 105

5.3.7 智能抗菌/防腐多功能涂层对碳钢SRB腐蚀防护性能... 106

5.4 本章小结... 107

第六章 结论与展望... 108

6.1 结论... 108

6.2 创新点... 109

6.3 展望... 109

参考文献... 111

附 录... 123

致 谢... 124

作者简历及攻读学位期间发表的学术论文与研究成果... 126