Engineering and control of surfactant-laden flows: multi-scale analysis and experiments

表面活性剂流动的工程和控制：多尺度分析和实验

• 批准号: EP/J010502/1
• 负责人: Omar Matar
• 金额: $ 42.85万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FJ010502%2F1
• 关键词: Engineering; control; surfactant; laden; flows

Over the past two decades, the use of surfactants as wetting agents has enjoyed considerable attention due to their importance and potential in a variety of industrial and biomedical applications (coating flows, detergency, enhanced-oil-recovery, treatment of respiratory distress syndrome). Despite the research in the area, numerous fundamental open problems remain, as no single approach (experiments, simulations or theory) in isolation is able to probe the formidable complexities of the fluid-solid behaviour of amphiphilic molecules in solution. This project will provide detailed understanding of how surfactants behave at contact lines and adsorb at interfaces, and how this ultimately affects the spreading and wetting of hydrophobic surfaces. In this context, even trivial-sounding problems are not fundamentally understood. For instance, although the equilibrium state of a surfactant-free droplet on a hydrophobic substrate is easily characterised using the Young equation, this is not the case when the droplet is laden with surfactant. How does the surfactant distribution equilibriate and the stresses induced by it balance with the forces at the contact line? How are the latter influenced by surfactant solubility, and the formation of surfactant aggregates at high surfactant concentrations? These questions underlie striking and technologically important, yet poorly eludicated effects, such as superspreading whereby aqueous droplets containing superspreader surfactants (e.g. trisiloxanes) spread rapidly to produce perfect wetting over hydrophobic substrates. The purpose of this proposal is to draw together three world-leading groupings to tackle these fundamental problems in a collaborative, systematic, multi-disciplinary and multi-scale manner. The chemistry and molecular interactions require detailed modelling on the molecular level: EAM brings this expertise. This must then be scaled up to the lengthscale of droplets and the application itself: RVC and OKM have considerable background in modelling surfactant-gradient (Marangoni) driven flows. The problem requires new physicochemical understanding of the phenomena and the developed models must be validated, and indeed informed by, detailed and careful experiments: VMS is a world-leader in both. The deep knowledge of surfactant-laden flows that will be achieved via the proposed, transformative research will be used not only to provide accurate and reliable predictions of these flows but also to rationally design bespoke surfactant molecular architectures for various applications ranging from agrochemicals to enhanced-oil-recovery.

在过去的二十年中，由于表面活性剂在各种工业和生物医学应用中的重要性和潜力（涂层流动性，去污力，增强油回收，呼吸窘迫综合征的治疗），表面活性剂作为润湿剂的使用受到了相当大的关注。尽管在该领域的研究，许多基本的开放问题仍然存在，因为没有一种孤立的方法（实验，模拟或理论）能够探测溶液中两亲分子的流体-固体行为的强大复杂性。该项目将提供详细的了解表面活性剂如何在接触线和吸附在界面上，以及如何最终影响疏水表面的扩散和润湿。在这种情况下，即使是听起来微不足道的问题也没有从根本上得到理解。例如，虽然疏水基底上的无表面活性剂的液滴的平衡状态容易使用Young方程表征，但当液滴负载有表面活性剂时情况并非如此。表面活性剂的分布如何平衡，以及由其引起的应力如何与接触线处的力平衡？表面活性剂的溶解度如何影响后者，以及在高表面活性剂浓度下表面活性剂聚集体的形成？这些问题是引人注目的和技术上重要的，但难以回避的效果，如超铺展，其中含有超铺展表面活性剂（如三硅氧烷）的水性液滴迅速铺展，以产生完美的润湿疏水基材。这项建议的目的是将三个世界领先的集团聚集在一起，以合作、系统、多学科和多规模的方式解决这些根本问题。化学和分子相互作用需要在分子水平上进行详细的建模：EAM带来了这方面的专业知识。然后，这必须按比例放大到液滴的长度和应用程序本身：RVC和OKM在模拟表面梯度（Marangoni）驱动流方面有相当大的背景。这个问题需要对这些现象有新的物理化学理解，开发的模型必须经过验证，并通过详细而仔细的实验得到信息：VMS在这两方面都处于世界领先地位。通过拟议的变革性研究实现的对表面活性剂负载流的深入了解不仅将用于提供这些流的准确和可靠的预测，而且还将用于合理设计定制的表面活性剂分子结构，用于从农用化学品到提高石油采收率的各种应用。

项目成果

Fluoro- vs hydrocarbon surfactants: Why do they differ in wetting performance?

• DOI: 10.1016/j.cis.2014.04.003
• 发表时间: 2014-08-01
• 期刊: ADVANCES IN COLLOID AND INTERFACE SCIENCE
• 影响因子: 15.6
• 作者: Kovalchuk, N. M.;Trybala, A.;Ivanova, N.
• 通讯作者: Ivanova, N.

Surfactant enhanced spreading of liquid drops on solid surfaces

表面活性剂增强液滴在固体表面上的铺展

• DOI: 10.1063/1.4906711
• 发表时间: 2015
• 作者: Karapetsas G

Influence of the Disjoining Pressure on the Equilibrium Interfacial Profile in Transition Zone Between a Thin Film and a Capillary Meniscus

分离压力对薄膜与毛细管弯月面过渡区平衡界面轮廓的影响

• DOI: 10.1016/j.colcom.2014.06.002
• 发表时间: 2014
• 期刊: Colloids and Interface Science Communications
• 作者: Kuchin I

Modeling the effect of surface forces on the equilibrium liquid profile of a capillary meniscus.

• DOI: 10.1039/c4sm01018c
• 发表时间: 2014-07
• 期刊: Soft matter
• 影响因子: 3.4
• 作者: I. V. Kuchin;O. Matar;R. Craster;V. Starov

Superspreading: mechanisms and molecular design.

• DOI: 10.1021/la5044798
• 发表时间: 2015-02
• 期刊: Langmuir : the ACS journal of surfaces and colloids
• 作者: P. Theodorakis;E. A. Müller;R. Craster;O. Matar