Nanomanufacturing of Surfaces for Energy Efficient Icing Suppression

用于节能结冰的表面纳米制造

• 批准号: EP/N006577/1
• 负责人: Manish K. Tiwari
• 金额: $ 12.82万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FN006577%2F1
• 关键词: Nanomanufacturing; Surfaces; Energy; Efficient; Icing

Undesirable ice formation causes a lot of disruption - from impairing energy efficiency of household refrigerators to causing destructive accidents due to ice accumulation on infrastructure components and airplanes. The proposed research aims to address this ubiquitous problem using precise, but potentially scalable techniques to nanoengineer icephobic surfaces that can suppress ice formation, resist impact of cold drops and have minimal adhesion to ice. The proposal is motivated to provide a viable, passive and energy efficient alternative to the currently employed anti-icing techniques, which rely either on electro-thermal systems that affect the system efficiency and running costs, or make use of environmentally adverse chemicals. The surface nanoengineering to be employed will involve a precise control of both the surface texture at nanoscale and the surface hydrophobicity. The appropriate combination of these two aspects is expected to not only suppress ice formation in severely supercooled conditions (at sub-zero temperatures), but to resist impact of high speed supercooled droplets and minimize adhesion of ice on the surface - all these aspects are relevant to icing in practical applications and will be tested in the current work.The ambition of the proposal is to make nanotextured surfaces with nanohole arrays with better than 10 nm precision (i.e. resolution). Such precise and rounded morphologies are expected to suppress ice formation according to the thermodynamic heterogeneous ice nucleation framework previously introduced by the PI and supported by atomistic modelling results in the literature. In addition, self-assembly of hydrophobic molecules on the surfaces will allow a control over the surface energy, which, in combination with the texture control, will help produce superhydrophobic surfaces that can resist impalement by high speed, cold drops, and have low ice adhesion. The drop impalement resistance can help avoid icing on aircrafts and outdoor infrastructure elements in freezing rain conditions. As a proof-of-concept for a potentially scalable, precise nanotexturing, current project will exploit electrochemical anodisation of metals through polymeric nanohole films, prepared using block-copolymers (BCP), serving as templates. The surface texturing will be limited to top ~100 nm or lower thickness of the substrate and only mild anodisation conditions will be used. The templated anodisation is well suited to aluminium and titanium - substrates prevalent in aerospace, refrigeration and automotive industry; however, similar templated etching approaches can be developed for substrates in other applications (see the PATHWAYS TO IMPACT section). PI's prior work has shown that thermally conductive substrates are better for arresting frost formation from cold drops lying on the surface, thus the metallic substrates are a very good choice. In addition, the current work, for the first time, introduces a novel means to use simple anodic surface projections to improve the resolution of BCP nanohole templates themselves to ~10 nm precision - surfaces anodised through these precise templates are expected to be ideally suited for icephobicity. The resulting anodised substrates will be rendered hydrophobic by functionalizing with hydrophobic molecules. These precisely nanotextured hydrophobic surface are expected to suppress icing not only due to their rounded nanoscale morphology, but will also feature minimal solid-liquid contact area, thereby further suppressing the icing probability. The synthesized surfaces will be subjected to three set of tests: their ability to resist impalement by high speed, supercooled drops (target: 25 m/s); ability to delay ice formation in supercooled conditions at different humidity levels (target: 2 hours at -25 degrees Centigrade); and minimize their adhesion to frozen (ice) drops.

不良的结冰会造成很多破坏 - 从损害家用冰箱的能源效率到由于基础设施部件和飞机上积冰而造成破坏性事故。拟议的研究旨在解决这个普遍存在的问题，使用精确但潜在可扩展的技术对疏冰表面进行纳米工程，可以抑制冰的形成，抵抗冷滴的影响，并且对冰的粘附力最小。该提案的目的是为目前采用的防冰技术提供一种可行、被动和节能的替代方案，这些技术要么依赖影响系统效率和运行成本的电热系统，要么使用对环境不利的化学品。所采用的表面纳米工程将涉及对纳米级表面纹理和表面疏水性的精确控制。这两个方面的适当组合预计不仅可以抑制严重过冷条件下（零度以下的温度）下的冰形成，而且可以抵抗高速过冷​​液滴的冲击并最大限度地减少冰在表面上的粘附 - 所有这些方面都是相关的该提案的目标是用纳米孔阵列制造纳米纹理表面，其精度（即分辨率）优于 10 nm。根据 PI 先前引入并得到文献中原子建模结果支持的热力学异质冰成核框架，这种精确和圆形的形态有望抑制冰的形成。此外，表面上疏水分子的自组装将允许控制表面能，这与纹理控制相结合，将有助于产生超疏水表面，该表面可以抵抗高速、冷滴的刺穿，并且具有低冰附着力。抗跌落刺穿性能有助于避免飞机和室外基础设施在冻雨条件下结冰。作为潜在可扩展的精确纳米纹理的概念验证，当前项目将通过使用嵌段共聚物（BCP）作为模板制备的聚合物纳米孔膜来利用金属的电化学阳极氧化。表面纹理将被限制在基底的顶部~100 nm或更低的厚度，并且仅使用温和的阳极氧化条件。模板阳极氧化非常适合航空航天、制冷和汽车工业中普遍使用的铝和钛基材；然而，可以为其他应用中的基材开发类似的模板蚀刻方法（参见影响途径部分）。 PI之前的工作表明，导热基材能够更好地阻止表面冷滴形成的霜，因此金属基材是一个非常好的选择。此外，目前的工作首次引入了一种新颖的方法，使用简单的阳极表面投影将 BCP 纳米孔模板本身的分辨率提高到约 10 nm 精度 - 通过这些精确模板阳极氧化的表面预计非常适合恐冰性。所得阳极氧化基材将通过疏水性分子功能化而呈现疏水性。这些精确的纳米纹理疏水表面不仅因其圆形纳米级形态而有望抑制结冰，而且还将具有最小的固液接触面积，从而进一步抑制结冰概率。合成表面将接受三组测试：抵抗高速过冷​​液滴刺穿的能力（目标：25 m/s）；能够在不同湿度水平的过冷条件下延迟结冰（目标：-25 摄氏度下 2 小时）；并尽量减少它们对冷冻（冰）滴的粘附。

项目成果

Compression molding processed superhydrophobic CB/CeO2/PVDF/CF nanocomposites with highly robustness, reusability and multifunction

压缩成型加工的超疏水 CB/CeO2/PVDF/CF 纳米复合材料具有高度坚固性、可重复使用性和多功能性

• DOI: 10.1016/j.colsurfa.2020.124533
• 发表时间: 2020-04-01
• 期刊: Colloids and Surfaces A: Physicochemical and Engineering Aspects
• 作者: Binrui Wu;Jiajie Lyu;Chaoyi Peng;Jun Liu;S. Xing;D. Jiang;S. Ju;M. Tiwari
• 通讯作者: M. Tiwari

All-organic superhydrophobic coatings with mechanochemical robustness and liquid impalement resistance.

全有机超疏水涂层具有机械化学稳定性和耐液体穿刺性。

• DOI: http://dx.10.1038/s41563-018-0044-2
• 发表时间: 2018
• 期刊: Nature materials
• 影响因子: 41.2
• 作者: Peng C

Nanotextured Aluminum-Based Surfaces with Icephobic Properties

具有疏冰特性的纳米纹理铝基表面

• DOI: 10.1080/01457632.2019.1640461
• 发表时间: 2020-11-12
• 期刊: Heat Transfer Engineering
• 影响因子: 2.3
• 作者: Michael Grizen;T. Maitra;J. Bradley;M. Tiwari
• 通讯作者: M. Tiwari