Fundamentals and Applications of Liquid Drop Interactions with Complex Surfaces

液滴与复杂表面相互作用的基础和应用

• 批准号: RGPIN-2017-05636
• 负责人: Amirfazli, Alidad
• 金额: $ 5.1万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691525
• 关键词: Fundamentals; Applications; Liquid; Drop; Interactions

The proposed research is a unique program that seeks to understand the behavior of complex surfaces and their interactions with liquid drops. Specifically, it will tackle areas of drop motion on a surface, fabrication of novel opto-fluidic devices based on liquid bridges, and drop impact onto complex (e.g. woven textile) surfaces. This research can produce the necessary knowledge to enable advanced technologies of strategic importance today, such as, energy systems (e.g. efficient condensers, and water management for fuel cells), protective textile and clothing, or biotechnology (e.g. accurate dispensing in PCR machines).***A comprehensive study of incipient motion of sessile drop arrangements placed on a simple (smooth hydrophobic or hydrophilic), or a complex (patterned) surface exposed to a shearing airflow will be done. We will seek relations between drop properties, arrangement geometry and air velocity for incipient motion of drops on a surface. Through surface engineering strategies we seek to further assist the shedding of drops, by a shearing airflow, using patterned surfaces with hydrophobic and hydrophilic regions.***Gaining fundamental knowledge about how to transfer liquids using a liquid bridge (e.g. used in dispensing and printing industries) is the key to advance such processes. We will study the complex case of bridges between non-parallel surfaces to understand the role of surface wettabilities, and dihedral angle between surfaces, in liquid transfer. In doing so we will consider liquid properties (surface tension, viscosity, etc.) and study both dynamic and quasi-static regimes. We have recently shown that by mechanically stimulating a liquid bridge, we can make a varifocal liquid lens; but to improve the response time of the lens, we will explore morphological changes of a liquid bridge under an electrical stress to develop novel optofluidic devices (e.g. a varifocal cylindrical lens). ***Simultaneous impact of multiple drops onto moving surfaces will be studied with the aim of understanding the impact morphology (e.g. splash limits, and resting drop shapes). Also, a systematic study of a single drop impact onto surfaces covered with a thin layer of an immiscible liquid will provide the fundamental information regarding the modes of drop-film interactions, e.g. film entrainment, bouncing, splashing, etc. A first comprehensive study of drop impact onto woven surfaces will allow determining the effectiveness of the claims made recently about protective nature of liquid infused or superhydrophobic textiles.***This proposal, at its core, is designed to provide training for 20 students at different levels. They will gain skills needed for Canada's knowledge based economy by working on advanced imaging systems, surface fabrication and characterization, as well as analytical and modeling techniques. Communication skills will be honed through disseminating their findings.**

拟议的研究是一个独特的项目，旨在了解复杂表面的行为及其与液滴的相互作用。具体来说，它将解决表面上的液滴运动区域、基于液桥的新型光流控器件的制造，以及液滴对复杂（例如纺织织物）表面的影响。这项研究可以产生必要的知识，以实现当今具有战略意义的先进技术，例如能源系统（例如高效冷凝器和燃料电池的水管理）、防护纺织品和服装或生物技术（例如 PCR 机器中的精确分配）。***对放置在简单（光滑疏水或亲水）或复杂（图案）表面上的固着液滴排列的初始运动进行全面研究 暴露于剪切气流中将完成。我们将寻找液滴特性、排列几何形状和表面上液滴初始运动的空气速度之间的关系。通过表面工程策略，我们寻求通过剪切气流、使用具有疏水性和亲水性区域的图案化表面来进一步帮助液滴脱落。***获得有关如何使用液桥（例如用于点胶和印刷行业）转移液体的基础知识是推进此类工艺的关键。我们将研究非平行表面之间桥的复杂情况，以了解表面润湿性和表面之间的二面角在液体转移中的作用。在此过程中，我们将考虑液体特性（表面张力、粘度等）并研究动态和准静态状态。我们最近表明，通过机械刺激液桥，我们可以制造变焦液体透镜；但为了提高透镜的响应时间，我们将探索电应力下液桥的形态变化，以开发新型光流控器件（例如变焦柱面透镜）。 ***将研究多个水滴同时撞击移动表面的情况，目的是了解撞击形态（例如飞溅限制和静止水滴形状）。此外，对单滴撞击覆盖有一层不混溶液体薄层的表面的系统研究将提供有关滴膜相互作用模式的基本信息，例如薄膜夹带、弹跳、飞溅等。首次对跌落对编织表面的影响进行全面研究，将有助于确定最近提出的有关液体注入或超疏水纺织品的保护性质的主张的有效性。***该提案的核心目的是为 20 名不同级别的学生提供培训。他们将通过研究先进的成像系统、表面制造和表征以及分析和建模技术，获得加拿大知识经济所需的技能。通过传播他们的发现，沟通技巧将得到磨练。**