Multiphase Multicomponent Lattice Boltzmann Method for Modelling Wetting on Liquid Infused Surfaces

液体注入表面（LIS）是一种新型的表面，灵感来自自然（猪笼草），排斥任何种类的液体。LIS通过用润湿润滑剂浸渍粗糙、多孔或纹理化表面来构造，从而赋予它们有利的表面特性，包括自清洁、防污和增强的传热。这些功能性表面具有解决广泛的社会、环境和工业挑战的潜力。例如，从家庭食物垃圾，其中超过20%是由于包装和残留物;到减轻热交换器结垢，估计占全球二氧化碳排放量的2.5%。尽管它们具有巨大的潜力，但是，迄今为止，由于缺乏坚固性和耐用性，LIS涂层在绝大多数应用中还不可行。在一个基本的水平上，润滑剂的存在下产生了一种新的，但了解甚少的一类润湿现象，由于丰富的薄润滑剂膜的动态和宏观液滴动态之间的相互作用，如液滴和延迟聚结之间的有效的长程相互作用。这也导致了许多开放的挑战，独特的LIS，如性能下降，由于润滑油耗尽。集成到这个EPSRC奖学金项目是一个创新的数值方法的基础上的格子玻尔兹曼方法（LBM）来解决运动方程的流体。LBM的一个关键优势是，关键的粗粒度的分子信息可以被纳入界面现象的描述，同时保持计算易处理的研究相关LIS的宏观流动动力学。LBM还高度灵活地考虑界面形状和拓扑结构的变化，复杂的表面几何形状，并且非常适合高性能计算。开发的模拟框架将是第一个可以完全解决LIS上润湿动力学复杂性的框架，代码将通过OpenLB开源。利用LBM模拟和四个项目合作伙伴的实验数据的支持，我将提供我们对LIS的理解急需的步骤变化。预期成果包括：（i）设计标准，最大限度地减少润滑剂消耗，被认为是LIS的主要弱点;（ii）新的见解液滴和润滑剂弯月面动力学LIS在广泛的润滑剂的可用性和润湿性条件;和（iii）液滴相互作用的定量模型LIS介导的润滑剂。这些关键挑战是大多数（如果不是全部）地雷影响调查应用程序所共有的。解决这些问题是更好地设计土地影响系统的唯一途径。最后，该项目中开发的计算工具和基本见解将被用来探索基于土地影响系统的两种潜在的颠覆性技术，这两种技术与可持续发展中的能源-水-环境关系密切。首先，我将研究在碳捕获中的应用，利用液体如何在LIS中固定，具有大的表面积与体积比，与埃克森美孚公司合作。更具体地说，基于液体胺的CO2捕集是一种重要的商业实践方法，但昂贵的基础设施和操作阻碍了其广泛实施。令人兴奋的是，LIS可能为使用液态胺的更经济的碳捕获方法提供解决方案。其次，鉴于目前全球水资源供需缺口达47%，以及减少表面活性剂使用的环境压力，我将与宝洁公司合作研究新的清洁方法。关键的想法是使用制剂液体的薄膜诱导固体表面上不需要的液滴的去湿，从而更局部地引入润湿性改变并且使用更少的资源。

Liquid infused surfaces (LIS) are a novel class of surfaces inspired by nature (pitcher plants) that repel any kind of liquid. LIS are constructed by impregnating rough, porous or textured surfaces with wetting lubricants, thereby conferring them advantageous surface properties including self-cleaning, anti-fouling, and enhanced heat transfer. These functional surfaces have the potential to solve a wide range of societal, environmental and industrial challenges. Examples range from household food waste, where more than 20% is due to packaging and residues; to mitigating heat exchanger fouling, estimated to be responsible for 2.5% of worldwide CO2 emissions.Despite their significant potential, however, to date LIS coatings are not yet viable in practice for the vast majority of applications due to their lack of robustness and durability. At a fundamental level, the presence of the lubricant gives rise to a novel but poorly understood class of wetting phenomena due to the rich interplay between the thin lubricant film dynamics and the macroscopic drop dynamics, such as an effective long-range interaction between droplets and delayed coalescence. It also leads to numerous open challenges unique to LIS, such as performance degradation due to lubricant depletion.Integral to this EPSRC Fellowship project is an innovative numerical approach based on the Lattice Boltzmann method (LBM) to solve the equations of motion for the fluids. A key advantage of LBM is that key coarse-grained molecular information can be incorporated into the description of interfacial phenomena, while remaining computationally tractable to study the macroscopic flow dynamics relevant for LIS. LBM is also highly flexible to account for changes in the interface shape and topology, complex surface geometry, and it is well-suited for high performance computing. The developed simulation framework will be the first that can fully address the complexity of wetting dynamics on LIS, and the code will be made available open source through OpenLB. Harnessing the LBM simulations and supported by experimental data from four project partners, I will provide the much-needed step change in our understanding of LIS. The expected outcomes include: (i) design criteria that minimise lubricant depletion, considered the main weakness of LIS; (ii) new insights into droplet and lubricant meniscus dynamics on LIS across a wide range of lubricant availability and wettability conditions; and (iii) quantitative models for droplet interactions on LIS mediated by the lubricant. These key challenges are shared by the majority, if not all, of LIS applications. Addressing them is the only way forward to better engineer the design of LIS.Finally, the computational tools and fundamental insights developed in the project will be exploited to explore two potentially disruptive technologies based on LIS, which are highly relevant for the energy-water-environment nexus in sustainable development. First, I will investigate application in carbon capture, exploiting how liquids can be immobilised in LIS with a large surface to volume ratio, in collaboration with ExxonMobil. More specifically, liquid amine-based CO2 capture is an important and commercially practised method, but the costly infrastructure and operation prohibit its widespread implementation. Excitingly, LIS may provide a solution to a more economical carbon capture method using liquid amine. Second, motivated by the current gap of 47% in global water supply and demand, as well as environmental pressure to reduce the use of surfactants, I will examine new approaches to clean in collaboration with Procter & Gamble. The key idea is to induce dewetting of unwanted liquid droplets on solid surfaces using a thin film of formulation liquid, thus introducing wettability alteration more locally and using much reduced resources.