Engineered Soft Materials and Interfaces

软材料代表着一种极其重要的材料类别，构成了一个数十亿美元的产业，由于缺乏将组成、加工和结构与性能联系起来的基本关系，仍然主要通过组合方法来配制。CRC计划将在两种重要的软材料上弥补这一缺口：乳状液和屈服应力悬浮液。乳状液是两种不相容的液体的混合物，其中一种液体以液滴的形式悬浮在另一种液体中。蛋黄酱、软饮料、乳霜、疫苗和油漆都是乳剂的例子。本节目将详细探讨两种与乳状液相关的现象：润湿和聚结。在许多应用中，微调乳状液的聚结和润湿速率对于获得所需的性能或特定功能至关重要，但以速率为重点的研究在文献中很少。为了解释这些现象的动力学，液滴与固体-流体或流体-流体界面之间的力将被测量到纳米牛顿的一小部分，同时使用内部仪器测量它们之间的分离。焦点的第二个软材料是颗粒-液体混合物(悬浮液)，它表现出屈服应力，即混合物在临界应力以下表现为固体，在临界应力以上表现为液体。牙膏、血液和钻井/压裂液都是屈服应力悬浮液的例子。悬浮液流动特性与悬浮液中存在的溶质传输速率(例如血液中的氧气和蛋白质、石油/天然气开采中的增粘剂和破胶剂等)之间缺乏关系，特别是在流动条件下，这是这一领域的一个关键缺陷。这项研究将通过在与共焦显微镜相结合的微流控装置中进行实验来填补这一空白，以揭示溶质传质速率的机理和定量细节。这项研究的知识和技术将导致从目前软材料的经验设计过渡到更系统、基于科学的设计，从而产生针对特定功能的乳状液，以及更高效的透析器、氧合器和钻井/压裂液添加剂。乳化液工业、生物医疗设备工业和石油工业是加拿大价值数十亿美元的产业。当受过该项目培训的HQP加入劳动力大军时，他们将为加拿大工业提供巨大的竞争优势。

Soft materials, which represent an extremely important material class and constitute a multi-billion dollar industry, are still formulated largely by combinatorial methods, due to a lack of the fundamental relationships that connect composition, processing, and structure, to properties. The CRC program will remedy this gap for two important soft materials: emulsions and yield stress suspensions.An emulsion is a mixture of two immiscible liquids in the form of drops of one liquid suspended in the other. Mayo, soft drinks, creams, vaccines, and paints are examples of emulsions. Two emulsion-related phenomena will be explored in detail in this program: wetting and coalescence. In many applications, it is critical to fine tune emulsion coalescence and wetting rates to achieve desirable properties or specific functions, but rate-focused studies are sparse in the literature. To elucidate the dynamics of these phenomena, the force between a drop and a solid-fluid or fluid-fluid interface will be measured down to a fraction of a nanoNewton, simultaneously measuring the separation between them down to a nanometer, using in-house instruments.The second soft material of focus is a particle-liquid mixture (suspension) that exhibits a yield stress, i.e. the mixture behaves like a solid below a critical stress, and like a liquid above it. Toothpaste, blood, and drilling/fracking fluids are examples of yield stress suspensions. The lack of relationships between suspension flow properties and the rate of transport of a solute present in the suspension (e.g. oxygen and proteins in blood, viscosifiers and gel breakers in petroleum/ gas extraction, etc.), particularly under flowing conditions, represents a key lacuna in this area. This research will fill the gap by performing experiments in a microfluidic setup coupled to a confocal microscope, to unearth mechanistic and quantitative details of solute mass transfer rates.The knowledge and technologies from this research will lead to a transition away from the current empirical design of soft materials to a more systematic, science-based design, resulting in emulsions tailored for specific functions, and more efficient dialyzers, oxygenators and drilling/fracking fluid additives. Emulsion-based industries, biomedical device industries and the petroleum industry are billion dollar industries in Canada. When HQP trained in the project join the workforce, they will provide Canadian industry a huge competitive edge.