Steering Colloids via Two-Dimensional Diffusiophoresis Using Crossed Gradients in Salt Concentrations

使用盐浓度的交叉梯度通过二维扩散电泳控制胶体

基本信息

批准号：
EP/V048473/1
负责人：
Joseph Keddie
金额：
$ 25.76万
依托单位：
University of Surrey
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FV048473%2F1
关键词：
Steering Colloids via Two Dimensional

项目摘要

Colloidal particles in liquids are found in many ordinary items, such as foods, paints, inks, cosmetics, and pharmaceuticals. They also are the "building blocks" for complex materials with attractive optical, mechanical or electrical properties. Colloids in liquid are not static, but they are constantly moving in random directions because of Brownian diffusion. In this research, we will investigate ways to move colloids in water in specific desired directions with exquisite control - thereby defying Brownian motion. When colloids have an electric charge they can be steered by an external electric field acting upon them through the mechanism known as electrophoresis. Recently, scientists have discovered that the electric fields created by gradients in salt concentration in water can drive colloid motion. The colloidal particles will move linearly either up or down a gradient in salt concentration, depending on the type of salt and whether the charge on the particles is positive or negative. Our vision in this project is to steer particles on curved paths by putting them in solutions in which there are gradients of two different salts going in directions at right angles to each other. We will use criss-crossed polymeric fibres to release salts into water as a way to devise complex patterns of salt concentrations. According to some recent calculations, it should be possible to use these salt gradients to separate mixtures of particles that differ in their charge. This new concept will allow particles to be sorted in a simple way, and at low-cost and without a need for an external power supply. An immediate application will be in re-using and recycling expensive nanoparticles to minimise their waste. The use of crossed gradients in salt concentration could also provide a way to measure unknown electric charges on particles. When the concept is validated in our experiments, it will provide the basis for a simple diagnostic method to identify and characterise particles, such as viruses or contaminants. Our research will show that crossed salt gradients can overcome Brownian motion to steer sub-micrometer particles on nearly any desired path. Having such precise control of colloid motion will open up possibilities for fabricating complex materials one particle at a time. We will attach some "sticky" molecules onto the colloids so that they will adhere to surfaces after being steered there by electrophoresis. Our fundamental research might thereby lead to breakthroughs in the manufacturing of materials for applications ranging from solar cells and optical devices to delivering drugs in the body.

液体中的胶体颗粒存在于许多普通物品中，例如食品、油漆、油墨、化妆品和药品。它们也是具有有吸引力的光学、机械或电气特性的复杂材料的“构建模块”。液体中的胶体不是静态的，但由于布朗扩散，它们不断地沿随机方向移动。在这项研究中，我们将研究通过精确控制使水中胶体向特定所需方向移动的方法，从而克服布朗运动。当胶体带有电荷时，它们可以通过作用在其上的外部电场通过称为电泳的机制来引导。最近，科学家发现水中盐浓度梯度产生的电场可以驱动胶体运动。胶体颗粒将沿盐浓度梯度线性向上或向下移动，具体取决于盐的类型以及颗粒上的电荷是正电荷还是负电荷。我们在这个项目中的愿景是通过将粒子放入溶液中来引导粒子沿着弯曲的路径行驶，在该溶液中存在两种不同盐的梯度，其方向彼此成直角。我们将使用纵横交错的聚合物纤维将盐释放到水中，以此设计复杂的盐浓度模式。根据最近的一些计算，应该可以利用这些盐梯度来分离电荷不同的颗粒混合物。这一新概念将允许以简单的方式、低成本地对颗粒进行分类，并且无需外部电源。一个直接的应用将是重新使用和回收昂贵的纳米颗粒，以最大限度地减少浪费。使用盐浓度的交叉梯度还可以提供一种测量颗粒上未知电荷的方法。当这个概念在我们的实验中得到验证时，它将为识别和表征颗粒（例如病毒或污染物）的简单诊断方法提供基础。我们的研究将表明，交叉盐梯度可以克服布朗运动，将亚微米颗粒引导到几乎任何所需的路径上。对胶体运动进行如此精确的控制将为一次制造一个粒子的复杂材料开辟可能性。我们将在胶体上附着一些“粘性”分子，以便它们在通过电泳引导后粘附在表面上。因此，我们的基础研究可能会在材料制造方面带来突破，这些材料的应用范围从太阳能电池、光学设备到体内输送药物。