石墨烯负载海洋天然提取物自催化钢筋阻锈剂的作用机理研究

Corrosion protection for reinforced concrete structures in marine engineering, which is of great concern to strategic emerging industries, plays a vital role in the sustainable development of blue economy. Novel organic migrating corrosion inhibitor has gradually gone to the cutting edge of concrete resistance research by replacing traditional inorganic corrosion inhibitor, owing to its inward penetrability and eco-friendly characteristic, and is getting to be the latest hotspot in marine engineering field. Nevertheless, with putting mechanisms into perspective, the study regarding validation and enhancement of inhibition effectiveness still appears to be a tough issue that very little systemic and deep-going discussion is available nowadays.This project clearly points out the theoretical feasibility to greatly enhance the corrosion inhibition efficiency via catalysing the cathodic oxygen reduction. Specifically, it intends to develop the efficient organic migrating corrosion inhibitor, which is typical of self catalysis, by innovatively grafting the marine natural extract onto graphene sheets as the functional nano-supporting material. Subsequently, using the high sensitivity electrochemical measurements, in situ tracking characterization techniques for product composition, time resolved microscopic imaging methods and non-destructive stereoscopic on-line corrosion sensors, it is aimed at elucidating the catalytic activity and mechanism of self catalytic corrosion inhibitor supported by graphene sheets, chemical interaction mechanism and microscopic three dimensional dynamics at the interface of inhibitor molecules and rebar in concrete under marine corrosion conditions, furthermore, establishing a quantitative analysis method for migration of corrosion inhibitor in concrete.The practice of this project would break through the key bottleneck of corrosion technology in marine engineering field. In addition, this study would further enrich and improve the theoretical foundation of failure control research for reinforced concrete structure, provide the effective instructions and substantial support for service life prolonging of marine infrastructures, decreasing energy consumption and limiting near shore ecological pollution.

海洋钢筋混凝土结构的腐蚀防护，是攸关蓝色经济可持续发展的重要新兴产业。新型有机迁移阻锈剂具有环境友好性和强力渗透性，逐步取代传统无机阻锈剂成为海洋工程防腐学术前沿关注的热点，而从作用机理入手验证和提高钢筋阻锈剂防腐性能的研究，一直是鲜有深入涉足和系统探讨的难点问题。本项目提出通过催化阴极氧还原，提高防腐性能的理论可行性和实现方案，拟采用新型功能纳米材料对海洋天然提取物进行化学负载，研制自催化型高效有机迁移阻锈剂，通过高灵敏度电化学测试、化合物原位追踪表征、时间分辨微观显像和无损立体式在线传感技术，阐明海洋腐蚀环境下纳米负载自催化阻锈剂的催化活性和机理、在钢筋表面的化学反应机理和三维动力学规律，建立混凝土内部阻锈剂迁移的定量分析方法。项目实施瞄准海洋工程防腐关键技术瓶颈，丰富和完善了钢筋混凝土腐蚀失效控制的理论研究基础，对延长海洋基础设施服役寿命、降低工程能耗和污染形成了理论指导和技术支撑。

钢筋腐蚀可造成沿海地区钢筋混凝土建筑过早劣化失效，严重制约了我国蓝色经济的可持续发展战略。有机钢筋阻锈剂技术作为氯盐腐蚀环境下钢筋混凝土结构工程中最简捷、经济和高效的防腐修复措施，正成为土木工程学术领域前沿所关注的热点。目前，对有机阻锈剂防腐性能的电化学分析仍存在理论误区，对其作用机理也尚未有深入研究，尤其缺乏原位微观的跟踪检测和无损直观的系统分析，另外，有机阻锈剂还存在防腐性能和零污染物排海量无法统筹兼顾的瓶颈制约。.本项目通过综合运用量子化学计算、灵敏电化学测试、化合物原位追踪分析表征、时间分辨原位显像技术，开展了氯盐腐蚀环境下负载海洋天然提取物阻锈剂分子与钢筋的原位化学反应机理研究，钢筋表面微观三维动力学研究，以及混凝土中的迁移作用机制研究：.（1）以量子化学构效关系计算为指导，合成与筛选了维生素和三氮唑类负载环境友好型有机阻锈剂化合物，优化了几何构型，计算了电荷密度分布和前线轨道能量；使用恒电量法对阻锈效率进行了快速评价，通过采用量子化学复合参数替代描述分子热力学性质的吸附平衡常数，建立了不受理想吸附假定条件限制的多元非线性构效关系方程，用以指导维生素类和三氮唑类阻锈剂化合物的快速效率评价和预测筛选。.（2）采用电化学交流阻抗谱（EIS）研究了相界型阻锈剂的防腐性能随浓度、温度和时间的变化规律，指出了传统阻锈剂电化学研究中的误区，确定了负载有机阻锈剂的最佳添加量浓度，发现阻锈效率的幂指数函数增长规律，描述了孔蚀诱导期和发展期，阻锈效率与温度呈现的负相关线性变化规律。.（3）提出了自钝化膜中有晶格和间隙两种不同能级粒子形成的假说，揭示了钝化膜破坏的原因；研究了阻锈剂在活化和钝态铁表面的纵向热力学吸附行为；建立了能够反映碱性溶液中相界型阻锈剂与铁表面自钝化膜作用机理的多间隙位尖晶石晶体结构模型。.（4）阐明了阻锈剂对混凝土孔结构的影响机理，采用了纳氏试剂分光光度法测试了阻锈剂在混凝土中的渗透迁移情况，考察了负载有机迁移型阻锈剂对混凝土耐久性的影响规律；利用砂浆中的快速腐蚀试验，评价了在海洋腐蚀环境下实际混凝土中的阻锈效果。.项目开展实施突破了海洋工程防腐关键技术瓶颈，丰富完善钢筋混凝土腐蚀失效控制的理论研究基础，对延长海洋基础设施服役寿命、降低工程能耗、遏制近岸生态污染形成了有效理论指导和切实技术保障。