纳米复合锌基防污电沉积层对典型海洋污损微生物的作用机制研究

Marine biofouling is a highly spontaneous process in which biofilm formation is considered as the most important step. Biofouling causes immense damages to marine steel constructions protected by zinc-based electrodeposits, so antifouling modification researches on zinc-based electrodeposits are extremely significant. However, present understanding of modification composite theories is still limited, and the reaction mechanisms of the composite zinc-based antifouling electrodeposits on typical marine fouling microorganisms remain unclear. Therefore in this project, antibiotic natural products analogues and reactive metal nanoparticles are planned to be composited into zinc-based electrodeposits to achieve antibacterial and sacrificing properties respectively. The co-deposition process of biocide and zinc ion will be systematically studied, so the composite theories can be proposed by tracing molecular structure of the biocide during electrodeposition. In order to calculate the corrosion rate for service life controlling, the relationship between composited reactive metal nanoparticles and fraction of corrosion products coverage on the electrodeposit surface will be quantified. Further research will be conducted on describing the antibiotic effects of the zinc-based antifouling electrodeposits on typical marine fouling microorganisms, illustrating the biofilm response on the electrodeposits, and ultimately clarifying the reaction mechanisms. This project aims at obtaining effective and green nanocomposite zinc-based antifouling electrodeposits, further clarifying the composite and reaction mechanisms, so as to provide fundamental basis for practical application in marine environment.

海洋生物污损是以微生物膜形成为重要步骤的高度自发过程，对锌基电沉积层防护的钢结构造成巨大破坏，因此开展锌基电沉积层的防污改性研究具有重要意义。然而，目前对锌基电沉积层防污复合原理的认识还非常有限，且改性电沉积层对典型海洋污损微生物的作用机制尚不明确。本项目拟以锌基电沉积层作为基础载体，复合天然产物类似物抗菌剂获得绿色抗菌性能，复合活性金属纳米颗粒获得牺牲性质，制备纳米复合锌基防污电沉积层；系统研究抗菌剂与锌的共沉积过程，跟踪抗菌剂存在形式，提出抗菌剂与锌基电沉积层复合原理；同时考察防污电沉积层中活性金属纳米颗粒复合量与腐蚀产物覆盖率关系，计算自腐蚀速率并调控寿命；进一步研究防污电沉积层对典型海洋污损微生物的杀灭作用，阐明防污电沉积层的生物膜响应，最终揭示作用机制。项目旨在获得绿色高效的纳米复合锌基防污电沉积层，明确其复合原理与作用机制，为实海应用提供理论基础。

锌基电沉积层常用于海洋水下关键构件如锚链、紧固件等防护，目前正在遭受着严重的生物污损问题，开展锌基电沉积层的防污改性研究具有重要意义。因此，本项目以锌基电沉积层为研究对象，复合海洋天然产物类似物有机抗菌剂和活性纳米颗粒作为功能性添加剂，设计制备了多种纳米复合锌基防污电沉积层，包括壳聚糖-锌电沉积层、壳聚糖-锌-镍复合电沉积层、辣椒素诱导纳米针ZnO/Zn电沉积层、二茂铁-锌复合电沉积层及纳米钒酸铋-锌复合电沉积层等；定性、定量描述了有机抗菌剂与锌的共沉积过程，明确了壳聚糖的活性氨基N与羟基O活位点、辣椒素的酰胺键-NH-活性位点等，进而提出了络合共沉积、物理诱导共沉积等复合原理；在有机抗菌剂复合量与纳米颗粒复合量交变影响下，阐明防污电沉积层在典型污损微生物环境下的相互影响机理，发现纳米复合锌基防污电沉积层能够有效抑制环境中硫酸盐还原菌等腐蚀污损微生物的生长代谢，并展现出增强的耐蚀防污性能。最后，明确了防污电沉积层对典型污损微生物的有机抗菌剂或活性自由基作用机制，证明了其抗菌广谱性，综合评价了多种纳米复合锌基防污电沉积层防污抗菌性能，发现其抗菌效率均在93%以上，最高抗菌效率可达99.96%。本项目提出了多种新型纳米复合锌基防污电沉积层，建立了电沉积参数及辅助条件优化方法，提出了有机抗菌剂的多种复合机理，最终明确了其抗菌防污作用机制，对锌基电沉积层的防污改性研究提供了借鉴，也为防污纳米复合锌基电沉积层的实海应用提供了重要参考。