Self-Organized Hierarchically Rough Ceramic Coatings

自组织分级粗糙陶瓷涂层

• 批准号: RGPIN-2014-05419
• 负责人: Nychka, John
• 金额: $ 1.46万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=567162
• 关键词: Self; Organized; Hierarchically; Rough; Ceramic

A considerable worldwide research effort has been devoted to understanding the water spreading or repelling nature of solid surfaces (wettability). Early research in textiles and mineral processing identified surface roughness and chemistry as the only variables responsible for wetting behavior, and a plethora of processing strategies have since been attempted to produce hydrophilic and hydrophobic surfaces, coatings, and composites for applications where solid and liquid phases interact. Of the explored manufacturing techniques and materials an extreme minority, if any, are widespread, commercially viable, stable, or durable. The lack of success in achieving stability and durability has been due to the predominant use of polymers; polymers are soft, wear intolerant, susceptible to morphological changes under low to moderate heat and stress, and are not entirely chemically or light resistant. The shortcomings of current materials strategies will be addressed in this project through the coating of metallic substrates with ceramic materials (e.g., oxides, sulfides, nitrides, and carbides) for applications ranging from corrosion protection, steam generation and coatings for enhanced boiling heat transfer. This proposal will investigate and focus on the materials design, coating architecture, processing, and characterization of ceramic coatings on metallic substrates. Ceramic coatings have the potential to be harder, inert, stable, and durable with an appropriate manufacturing such as oxidation synthesis (heating a metal in laboratory air). The long-term engineering vision for this project is to discover a process whereby ceramic coatings can be manufactured in situ on a metallic surface in a self-organized fashion with inherent capability to tune their wettability through well-identified and controlled process variables. The research team (HQP) will be trained in and study, generation and dissemination of knowledge concerning the fundamental materials science and engineering challenges associated with creating ceramic coatings on metallic substrates. The three main program objectives are: 1) design, fabricate, and assess hierarchical roughness architectures for hydrophilic and hydrophobic response (pore structure and relative volume and interconnectedness, material selection, coating method, surface chemistry, hydroxyl content, C contamination, charge distribution). A variety of materials and coating systems will be investigated at this stage chosen by thermodynamic stability and compatibility; 2) characterization, phase identification, kinetics and thermodynamics analysis of ceramic component systems suitable for modeling and prediction of materials and coating performance (crystallography, surface wettability under varying relative humidity and temperature); 3) subject materials system to high temperature and moist environments to assess and prevent, through materials, processing, and coating architecture design, any deleterious structural evolution leading to topological, or surface chemistry changes alter wettability (microscopy, roughness changes, contamination, phase separation, and associated apparent contact angle changes). Coating techniques which can control both surface topography and chemistry will be investigated: 1) Oxidation Synthesis whereby coatings will be grown through reaction with gaseous environments to produce rough crystallites; 2) Sol-Gel Processing whereby a rough coating from oxidation synthesis will be coated with a ceramic of low polar surface free energy (rare earth oxides) which will also be rough; and 3) Spinodal Decomposition whereby ceramic coatings will decompose to produce rough coatings. Impact will be widespread and seen in many industries from corrosion control to energy production.

全球研究工作的大量研究旨在理解固体表面（润湿性）的散布或排斥性质。对纺织品和矿物加工的早期研究将表面粗糙度和化学识别为负责润湿行为的唯一变量，此后已尝试生产多种处理策略，以生产固体和液体相互作用的应用，用于生产水文和疏水性表面，涂料和复合材料。在经过探索的制造技术和材料中，极少数（如果有的话）是广泛的，商业上可行的，稳定的或耐用的。缺乏实现稳定性和耐用性的成功是由于聚合物的主要使用。聚合物柔软，磨损不耐受，在低至中等的热量和压力下易受形态变化，并且并非完全具有化学性能或耐轻度。该项目将通过用陶瓷材料（例如氧化物，硫化物，硝酸盐和碳化物）涂层当前材料策略的缺点，以从腐蚀保护，蒸汽产生和涂料等涂层，以增强沸腾的热传递。 该建议将调查并关注金属底物上陶瓷涂层的材料设计，涂料结构，加工和表征。陶瓷涂料有可能具有适当的制造（例如氧化合成）（在实验室空气中加热金属），有可能变得更硬，惰性，稳定和耐用。该项目的长期工程愿景是发现一个过程，即可以以自组织的方式在金属表面上原位制造陶瓷涂层，具有固有的能力，可以通过识别良好和受控的过程变量调整其润湿性。 研究团队（HQP）将接受培训，研究，生成和传播有关基本材料科学和工程挑战与在金属底物上创建陶瓷涂料相关的知识。三个主要程序目标是：1）设计，捏造和评估用于亲水和疏水响应的分层粗糙度体系结构（孔结构以及相对体积和互连性，材料选择，涂料方法，表面化学，羟基含量，羟基含量，C污染，电荷分布）。在此阶段将通过热力学稳定性和兼容性选择各种材料和涂料系统。 2）对陶瓷组件系统的表征，相识别，动力学和热力学分析，适用于材料和涂料性能的建模和预测（晶体学，相对湿度和温度不同）； 3）主题材料系统是高温和潮湿的环境，以评估和预防材料，加工和涂料结构设计，任何有害结构进化，导致拓扑或表面化学的变化改变了润湿性（显微镜，粗糙度的变化，污染，相位分离，相位分离以及相关的明显接触角变化）。 将研究可以控制表面形貌和化学的涂料技术：1）氧化合成，从而通过与气态环境的反应来生长涂料，以产生粗糙的结晶； 2）溶胶 - 凝胶加工，从而将氧化合成的粗糙涂层与低极性表面自由能（稀土氧化物）的陶瓷涂覆，这也将是粗糙的； 3）旋律分解，陶瓷涂料将分解以产生粗糙的涂料。从腐蚀控制到能源生产的许多行业，影响将是广泛的，并且可以看到。