新型尿嘧啶类铜缓蚀剂分子设计的理论研究

Copper corrosion has attracted extensive attentions nowadays because it occurs in diverse fields which is very important for national economic development. One of the useful methods to control the corrosion process is the addition of corrosion inhibitor to protect the metal surface from the corrosion environment. The purpose of this project is to design and develop novel, efficient, and environment-friendly uracil-based copper corrosion inhibitors. In this project, quantum chemistry and dynamical methods have been employed to reveal the corrosion inhibition mechanism and the thermodynamic and kinetic behavior of the whole interaction process through the systematical investigations of the interaction mechanisms between uracil derivatives inhibitors and copper surface as well as their behavior of the adsorption-desorption. We will clarify the evolution law of the inhibition process and establish the correlations between inhibition efficiencies and the structural and property parameters of the corrosion inhibitors so as to achieve the predictability and controllability of the inhibition efficiencies. Moreover, we can gain the optimal parameter indexes for the various factors associated with the inhibition efficiency through the investigations of the effects of temperatures, pressures, and pH values of the medium on the inhibition efficiency. These insights can not only provide the scientific basis and the theoretical guidance for the experimental synthesis and screening of the novel corrosion inhibitors, but also give new clues to the molecular designs of the other metal corrosion inhibitors.

铜的腐蚀遍及国民经济的各个领域，已引起全世界的广泛关注，而添加缓蚀剂则是一种行之有效的防腐方法。围绕新型、高效、环境友好型铜缓蚀剂的设计开发，本项目运用基于第一性原理的量子化学和动力学方法，以尿嘧啶及其衍生物为研究对象，通过系统探讨缓蚀过程中缓蚀剂与Cu表面的作用机制及其吸附-脱附行为，明确缓蚀剂的缓蚀机制及缓蚀过程中的热动力学行为，揭示缓蚀体系的演化规律；建立缓蚀性能与缓蚀剂分子结构及性质参数之间的相关性，实现对缓蚀性能的可调控性和可预测性。通过考察温度、压强、介质酸碱性等各种因素对缓蚀性能的影响，获得不同条件下缓蚀剂分子发挥最佳缓蚀性能时的各项参数指标。该项目的开展不但可为新型、高效、环境友好型铜缓蚀剂的实验合成与筛选提供必要的科学依据和理论指导，而且也可为其它金属缓蚀剂的分子设计提供新思路。

铜的腐蚀遍及国民经济的各个领域，已引起全世界的广泛关注，而添加缓蚀剂则是一种行之有效的防腐方法。围绕新型、高效、环境友好型铜缓蚀剂的设计开发，本项目运用基于第一性原理的量子化学和动力学方法，利用周期性平板模型，系统探讨了尿嘧啶及其二硫代衍生物在铜的三个晶面（110）、（100）、（111）上的吸附模式、吸附强度及作用机制。研究发现，缓蚀剂分子在金属表面上的吸附模式、吸附强度与金属的晶面有关。并且，尿嘧啶类缓蚀剂的缓蚀性能对介质的pH值具有强烈的依赖性。硫取代能显著提高尿嘧啶的吸附强度和缓蚀性能，但缓蚀性能与吸附强度及缓蚀剂与金属之间的电荷转移量并无直接相关性。通过对缓蚀剂吸附前后的铜及缓蚀剂分子的态密度分析，进一步阐明了缓蚀剂的缓蚀机制及缓蚀过程中的热动力学行为，揭示了缓蚀体系的演化规律；建立了缓蚀性能与缓蚀剂分子结构及性质参数（如HOMO-LUMO能隙、偶极矩）之间的相关性，实现了对缓蚀剂缓蚀性能的可预测性。基于尿嘧啶分子，发现甲基化的二硫代尿嘧啶是潜在的高效铜缓蚀剂。此外，我们还系统考察了部分天然氨基酸（如半胱氨酸）在铜表面上的吸附行为，通过结构修饰的方法，发现修饰后的氨基酸也可以作为潜在的铜缓蚀剂。该研究结果不但可为新型、高效、环境友好型铜缓蚀剂的实验合成与筛选提供必要的科学依据和理论指导，而且也可为其它金属缓蚀剂的分子设计提供新思路，具有重要的借鉴意义。