钢表面仿生免修饰超疏水Cu-Zn-CeO2层的制备及其协同防垢行为研究

Scaling is one of the serious issues encountered in oil and gas well pipe, ground gathering pipeline and equipment. The presence of the scaling can cause pipeline blockage, resulting in tremendous damage and loss to production. However, the effect of only one anti-scaling method is often unsatisfactory. It is necessary to take a composite anti-scaling method. Based on the principle of surface bionics, steel as the substrate, an ultrasound-assisted composite electrodeposition method is used to fabricate a bionic superhydrophobic Cu-Zn-CeO2 coating without low energy modification. The effects of different process conditions and parameters on the surface micro-nano hierarchical structure and the wetting law are investigated to optimize the preparation process. Meanwhile, the relevant theoretical model about surface wettability is fabricated, combined with theory, simulation, and calculation, to clarify the hydrophobic mechanism of the bionic modifier-free superhydrophobic Cu-Zn-CeO2 coating. By comparing scaling characteristics of the bionic modifier-free superhydrophobic Cu-Zn-CeO2 coating and the steel substrate surface, the synergistic anti-scaling behavior of the Cu-Zn anti-scaling alloy and the superhydrophobic surface are investigated. Moreover, the anti-scaling model is fabricated to explore its synergistic anti-scaling mechanism. Various ways are used to investigate its hydrophobic stability and durability such as corrosion resistance and abrasion resistance. The research results are the enrichment and development of the theory and technology of surface wetting, and also provide technical support and theoretical basis for solving the scaling problem of oilfield pipelines.

结垢是油气井管、地面集输管线和设备遇到的严重问题之一，垢的存在会造成管线堵塞，给生产带来巨大的危害和损失。然而，仅一种防垢措施的效果往往不尽人意，有必要采取复合防垢措施。本项目基于表面仿生学原理，以钢材为基底，采用超声波辅助的复合电沉积法，不经过低能修饰，制备仿生超疏水Cu-Zn-CeO2层。考察不同工艺条件和参数对其表面微纳米多级结构和润湿规律的影响，进而优化其制备工艺，同时建立相应的表面润湿理论模型，结合理论模拟计算，阐明仿生免修饰超疏水Cu-Zn-CeO2层的疏水机制。通过对比仿生免修饰超疏水Cu-Zn-CeO2层与钢基体表面的结垢特性，研究Cu-Zn防垢合金和超疏水表面的协同防垢行为，同时构建防垢模型，探索其协同防垢机理。采用多种途径研究其表面的疏水稳定性及耐蚀性、耐磨性等耐久性。研究成果是对表面润湿理论与技术的丰富和发展，也为解决油田管道存在的结垢问题提供技术支持和理论依据。

结垢是油气管线等遇到的严重问题之一，仅一种防垢措施的效果往往不尽人意，有必要采取复合防垢措施。本项目采用电沉积法首先通过参数优化在管线钢基体上制备了多尺度Cu-Zn-CeO2层，不经低表面能改性，在空气中放置35天实现了超疏水性。通过表面微观分析和构建吸附模型，发现碳氢化合物的吸附对多尺度Cu-Zn-CeO2层的超疏水性起着重要作用。电沉积层表面最初因存在空位等缺陷，表面能高，呈现超亲水；在空气中放置后表面缺陷处发生羟基化，而后不断吸附烃类分子，表面能显著降低，实现了超疏水。通过形核理论和润湿理论对其防垢行为和机理进行了分析，免修饰超疏水Cu-Zn-CeO2层将超疏水性和Cu-Zn合金的防垢功能相结合，对CaCO3的结晶过程同时起到成核抑制和成核诱导的作用，有效地抑制了方解石CaCO3在表面的成核和生长，从而起到协同防垢的效果。随后，在管线钢基体上制备了多尺度电沉积Cu层，在空气中放置15天即实现了超疏水性。通过表面微观表征，构建了免修饰超疏水Cu层的吸附动力学曲线模型，定量分析了碳氢化合物的吸附与润湿性转变的关系。多尺度分级结构有利于碳氢化合物的吸附，缩短了超亲水向超疏水转变的时间。基于经典Wenzel和Cassie理论，验证了免修饰多尺度电沉积层实现超疏水性的合理性。此外，在管线钢基体上制备了多尺度电沉积Ni-CeO2层，经100℃真空处理12h后即实现了超疏水性，明显缩短了制备时间。对比分析了微观结构、成分、CeO2以及真空、加热对润湿性的影响。免修饰超疏水Ni-CeO2层在静态和动态条件下均表现出良好的防垢性。最后，使用分子动力学模拟建立了纳米尺度和宏观尺度水滴的关系，研究了水滴在超疏水表面的运动机制；验证了双尺度微结构对Cassie状态的形成和稳定性的重要性。研究结果丰富和发展了仿生表面润湿领域的理论和技术，并为解决防垢问题奠定了理论和技术支撑。