The effect of surface patterning on corrosion of metals

了解表面能和表面拓扑在天然非润湿表面中的互补作用，导致了许多仿生疏水表面的发展。两个不同的现象解释了所观察到的疏水性的性质。一方面，这些表面的粗糙度显著增加，这增加了固体的总表面积。另一方面，这种“粗糙度”允许在液体下方形成亚稳气穴，导致液体部分悬浮在非均质气固界面上。基于这种疏水（低或不可湿性）表面减少固体表面与电解质（腐蚀剂）之间的实际接触面积的想法，推导了一种可能的抗腐蚀方法。这种方法的实质是在固液界面处实现稳定的非均相润湿。由于腐蚀现象的表面性质，非均匀润湿和由此产生的接触面减少应导致总体腐蚀速率的显着降低。在亲水材料上形成非均相界面的挑战在于设计能够导致稳定空气/蒸汽夹持的表面形貌。***提出的研究的主要目标是开发人工表面织构来控制金属表面的腐蚀。主要的重点将是开发包含0.1到100微米尺度结构的结构表面。建议的表面形态将通过激光烧蚀和深度反应离子蚀刻（DRIE）产生。本研究将尝试提供对表面纹理现象的深入研究。因此，该研究通过增加理解和证明在广泛应用中采用表面纹理的可行性，有望在现有技术的防腐方面取得重大进展。*****

Understanding the complementary roles of surface energy and surface topology in natural nonwetting surfaces has led to the development of many biomimetic hydrophobic surfaces. Two distinct phenomena explain the nature of the observed hydrophobicity. On one hand, the roughness of such surfaces is significantly increased, which increases the overall surface area of the solid. On the other hand, such “roughness” allows for the formation of metastable air pockets trapped below the liquid, which results in partially suspended liquid on heterogenous air-solid interface. Based on the idea that such hydrophobic (low or non-wettable) surfaces reduce the actual contact area between the solid surface and the electrolyte(corrosion agent), a possible approach to combat corrosion was deducted. The essence of such approach is to achieve stable heterogeneous wetting at the solid-liquid interface. Due to the surface nature of the corrosion phenomenon the heterogeneous wetting and the resulting reduction in contact surface should lead to a significant reduction in the overall corrosion rate. The challenge in forming heterogeneous interfaces on hydrophilic materials lies in designing surface topographies that will lead to stable air/vapor entrapment.***The main goal of the proposed research is to develop artificial surface texturing to control corrosion on metallic surfaces. The primary focus will be on developing structured surfaces containing structures on a scale of 0.1 to 100 microns. The suggested surface morphologies will be created by using laser ablation and Deep Reactive Ion Etching (DRIE). The proposed research will attempt to provide in-depth study of the surface texturing phenomena. Thus, the research promises a major advance on prior art in corrosion protection by increasing the understanding and demonstrating the feasibility of adopting surface texturing in wide range of applications.*****