Probing and directing colloidal migration by sculpting chemical micro-environments

通过塑造化学微环境来探测和指导胶体迁移

基本信息

批准号：
1438779
负责人：
Todd Squires
金额：
$ 31.88万
依托单位：
University of California-Santa Barbara
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2018-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1438779&HistoricalAwards=false
关键词：
Probing directing colloidal migration sculpting

项目摘要

CBET 1438779Many materials of industrial and biological importance consist of small colloidal particles suspended in a liquid. The particles are so small that they move in response to various forces exerted on them by their surroundings. This project will study diffusiophoresis, which is the motion of colloidal particles in response to concentration variations of a dissolved solute such as salt in the liquid. A microfluidic-based device will be developed that can create and maintain solute concentration gradients in a liquid. Then, the motion of colloidal particles in the liquid will be observed directly and correlated with the direction and magnitude of the concentration gradient. A variety of particles and different kinds of solute concentration gradients will be examined. Although there have been theories developed to explain diffusiophoresis, there are few experiments available to test those theories. The results will help scientists and engineers formulate and process colloidal suspensions that are used in a variety of industries. The project will provide research training opportunities for graduate and undergraduate students and will engage elementary school students in demonstrations of engineering principles and applications.Although colloidal diffusiophoresis plays a central role in industrial and coating processes, and is common around equilibrating or reacting surfaces, it is less well understood than other migration phenomena such as electrophoresis. Direct measurements of diffusiophoretic mobilities are confounded by the challenges of establishing strong, stable, convection-free gradients in macroscopic systems. This project will use a microfluidic device that has hydrogel micro-window membranes integrated into its channel walls. The hydrogel windows are permeable to solute and solvent diffusion. Diffusion through the windows will allow spatial and temporal solute gradients to be established and maintained across selected channels of the device. An interferometric technique will be used to measure solute concentration, and colloidal diffusiophoretic mobility will be measured by direct observation of particle motion. The device will also be equipped to measure electrophoretic mobility of the same colloid. New phoretic phenomena will be identified and exploited for direct assembly of structure soft materials.

CBET 1438779许多具有工业和生物重要性的材料由悬浮在液体中的小胶体颗粒组成。这些粒子是如此之小，以至于它们会响应周围环境施加的各种力而移动。该项目将研究扩散电泳，即胶体颗粒响应溶解的溶质（例如液体中的盐）的浓度变化而运动。将开发一种基于微流体的设备，可以在液体中产生并维持溶质浓度梯度。然后，将直接观察液体中胶体颗粒的运动，并将其与浓度梯度的方向和大小相关联。将检查各种颗粒和不同种类的溶质浓度梯度。尽管已经发展了一些理论来解释扩散电泳，但很少有实验可用来检验这些理论。研究结果将帮助科学家和工程师配制和加工用于各种行业的胶体悬浮液。该项目将为研究生和本科生提供研究培训机会，并将让小学生参与工程原理和应用的演示。尽管胶体扩散电泳在工业和涂层过程中发挥着核心作用，并且在平衡或反应表面方面很常见，但它与电泳等其他迁移现象相比，这一现象不太容易被理解。扩散电泳迁移率的直接测量因在宏观系统中建立强、稳定、无对流梯度的挑战而受到困扰。该项目将使用一种微流体装置，该装置将水凝胶微窗膜集成到其通道壁中。水凝胶窗口可渗透溶质和溶剂扩散。通过窗口的扩散将允许在设备的选定通道上建立和维持空间和时间溶质梯度。将使用干涉技术来测量溶质浓度，并通过直接观察粒子运动来测量胶体扩散电泳迁移率。该设备还将配备用于测量同一胶体的电泳迁移率。新的电泳现象将被识别并用于结构软材料的直接组装。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Probe microrheology without particle tracking by differential dynamic microscopy

通过差动动态显微镜无需颗粒跟踪即可探测微流变学

DOI：
10.1007/s00397-017-1047-7
发表时间：
2017-11
期刊：
Rheologica Acta
影响因子：
2.3
作者：
Bayles, Alexandra V.;Squires, Todd M.;Helgeson, Matthew E.
通讯作者：
Helgeson, Matthew E.

Design strategies for engineering soluto-inertial suspension interactions

工程溶液-惯性悬浮相互作用的设计策略

DOI：
10.1103/physreve.100.052603
发表时间：
2019-11
期刊：
Physical Review E
影响因子：
2.4
作者：
Banerjee, Anirudha;Vogus, Douglas R.;Squires, Todd M.
通讯作者：
Squires, Todd M.

Anomalous Solute Diffusivity in Ionic Liquids: Label-Free Visualization and Physical Origins

离子液体中的反常溶质扩散率：无标记可视化和物理起源

DOI：
10.1103/physrevx.9.011048
发表时间：
2019-03
期刊：
Physical Review X
影响因子：
12.5
作者：
Bayles, Alexandra V.;Valentine, Connor S.;Überrück, Till;Danielsen, Scott P. O.;Han, Songi;Helgeson, Matthew E.;Squires, Todd M.
通讯作者：
Squires, Todd M.

Hydrogen Bonding Strength Determines Water Diffusivity in Polymer Ionogels

氢键强度决定聚合物离子凝胶中的水扩散率

DOI：
10.1021/acs.jpcb.1c01460
发表时间：
2021-05
期刊：
The Journal of Physical Chemistry B
影响因子：
0
作者：
Bayles, Alexandra V.;Fisher, Julia M.;Valentine, Connor S.;Nowbahar, Arash;Helgeson, Matthew E.;Squires, Todd M.
通讯作者：
Squires, Todd M.

Dark-field differential dynamic microscopy

暗视野微分动态显微镜