非共价改性与外场耦合协同增强石墨烯复合涂层导热防腐性能

Graphene has ultra-high thermal conductivity and is impermeable to molecules, so that it has unique advantages in the corrosion protection of heat exchangers. Excessive graphene loading can ensure the thermally-conductive performance of coatings, however, it also damages the coating integrity and reduces the coating corrosion resistance. Therefore, efficient use of graphene is a key issue in applying graphene for the protection of heat transfer equipment . In this project, non-covalent functionalized graphene is used as fillers. Under the premise of greatly improving the corrosion resistance of coating, the project focuses on improving the thermal conductivity of the coating by the combination of regulating the fine structure of interface and the ordering of the microstructure of composite materials. The project will develop a method that can prepare high-performance thermal and anti-corrosive coatings from microscopic levels. Firstly, the influencing mechanism of the fine structure of modified graphene-liquid crystal epoxy interface on the thermal conductivity and corrosion resistance of the composite coating will be studied in detail. Then, the electric field and shear force field will be used combinedly to induce the ordering of the composites microstructure, and the improvement degree of thermal conductivity and corrosion resistance of the composite coatings will also be studied thoroughly. The inherent mechanism that how the graphene modification, the fine structure of the interface and the microstructure influence the thermal conductivity and corrosion resistance of the composite coating will be investigated finally. The project will provide a theoretical basis for the preparation of coatings with high thermal conductivity and corrosion-resistant from the perspective of molecular modification and microstructure design, which is of great significance to solve the corrosion problem of heat exchangers.

石墨烯具有超高的导热系数和耐分子渗透的特性，在换热设备防腐领域具有得天独厚的优势。然而，过量混入石墨烯虽能保证涂层的导热性能，但却会破坏涂层的整体性及防腐性能。因此，高效利用石墨烯是它在换热设备领域应用的关键。本项目采用非共价改性石墨烯作为填料，在显著改善涂层防腐性能的前提下，重点通过调控界面精细结构、促进微观形貌有序化两方面提高涂层的导热性能，优化石墨烯用量，在微观层面上实现高性能导热防腐涂层的研发。首先，详细研究改性石墨烯-液晶环氧树脂界面的精细结构对复合涂层导热与防腐性能的影响机理。然后，将电场与剪切场耦合，协同诱导复合材料微观结构的有序化，并深入研究有序结构提升复合涂层导热与防腐性能的程度，揭示石墨烯改性、界面精细结构、材料微观形貌影响涂层导热与防腐性能的内在机制。本项目将从分子改性、涂层微结构设计的角度为制备高性能导热防腐涂层提供理论依据，对解决换热设备的腐蚀问题具有重要的意

石墨烯的优异导热性能和耐分子渗透特性，使其在换热设备防腐领域具有广阔的应用前景。虽然，随着石墨烯载量的增加，石墨烯复合涂层的导热性能改善，但过量混入石墨烯却会破坏涂层的防腐蚀性能。因此，高效地利用石墨烯是其在换热设备领域应用的关键。本项目采用非共价改性石墨烯作为导热防腐填料，在显著改善涂层防腐性能的前提下，重点通过调控界面精细结构、促进微观形貌有序化两方面提高涂层的导热性能，降低石墨烯的用量，在微观层面上实现了高性能导热防腐涂层的研发。研究发现，多层石墨烯表面1-芘甲胺覆盖率约为10.5%、载量为5%时复合涂层的综合导热防腐性能最优，其导热系数可达0.64 W/(m·K)，浸泡6个月其电化学交流阻抗的低频模值仍保持在10^9 Ω·cm^2以上；但载0.5%以下的石墨烯时，调控电场与剪切场耦合作用使石墨烯定向排列角度为36°~54°，复合涂层的综合导热防腐性能最优；然而，由于空间位阻，但载0.5%以上的石墨烯难以通过耦合场实现石墨烯的取向排列调控；复合涂层的导热机理与聚合物内石墨烯三维网络的构型、石墨烯填料内“导热高速公路”的畅通、填料-聚合物界面热阻的降低等密切相关，而其防腐机理只与聚合物内石墨烯三维网络的构型有关。本项目将从分子改性、涂层微结构设计的角度为制备高性能导热防腐涂层提供理论依据，对解决换热设备的腐蚀问题具有重要的意义。