Active matter transport by non-electrolyte diffusiophoresis

CBET -1603716 PI：Velegol，Darrell该项目的目标是通过一种称为扩散电泳的过程来了解微米级胶体颗粒的运动。 当溶解在液体中的分子不均匀地分布在颗粒周围时，小颗粒可以在液体中移动。 颗粒的速度受溶质分子和颗粒之间的化学相互作用的影响，这是由经验相互作用参数描述。 该项目将使用基于计算机的方法来预测相互作用参数，从而预测粒子的速度，用于各种溶质，包括盐，聚合物，纳米粒子和其他物种。 该项目将侧重于非电解质溶质，无论是水性还是有机物，以扩大自推进颗粒可用于输送货物或增强混合的介质范围。 这些介质包括地质储层、生命系统和电子设备。 使用基于计算机的模型来预测粒子速度的优点是不必对每个不同的系统进行昂贵的实验。 相反，基于溶质和粒子之间分子水平力的基本描述的计算机方法可以预先使用。 然后，利用计算机计算的结果，研究小组将合成颗粒，这些颗粒可以在其表面周围产生不均匀的溶质分布，以产生自推进运动。 该项目的成果将用于题为“创造力、创新和变革”的在线课程。“电解质扩散电泳作为推进机制的实用性是有限的，特别是在高盐浓度和介电（非极性）介质中，许多关键应用在于。 这个项目探讨非电解质扩散电泳，其中一个粒子产生局部浓度梯度的非电解质物种，造成自我推进。 知识的关键差距是系统化学和自推进粒子的速度之间的联系。本项目将根据粒子和非电解质溶质之间的货车德瓦耳斯吸引力和硬球排斥力的严格描述，开发计算相互作用能的方法。 有了这些能量，就可以计算化学相互作用参数和粒子速度。 该项目还将构建自推进粒子，其中包含适当的含二茂铁聚合物，金纳米粒子，有机金属催化剂和其他物种。 所得到的动力化学将包括具有适当材料、尺寸和结构的吸引或排斥部分，以在给定的一组溶液条件下引起运输。根据已知的反应动力学，将计算浓度梯度，并首次测量相互作用参数的值。成功的衡量标准包括在三个具有挑战性的试验床中观察非电解质扩散电泳运输：含5 M盐的水溶液、生理液体和己烷。

CBET - 1603716PI: Velegol, DarrellThe goal of this project is to understand the movement of micrometer-size colloidal particles by a process called diffusiophoresis. Small particles can move through a liquid when molecules dissolved in the liquid are distributed unevenly around the particle. The velocity of the particle is affected by chemical interactions between the solute molecules and the particle, which are described by an empirical interaction parameter. This project will use computer-based methods to predict the interaction parameter, and hence the speed of the particle, for various solutes including salt, polymers, nanoparticles and other species. The project will focus on non-electrolyte solutes, whether aqueous or organic, to broaden the range of media in which self-propelled particles can be designed to deliver cargo or enhance mixing. These media include geological reservoirs, living systems, and electronic devices. The advantage of using computer-based models to predict particle speed is that expensive experiments do not have to be carried out for each distinct system. Instead, the computer methods, which are based on fundamental descriptions of molecular level forces between the solute and the particle, can be employed in advance. Then, using results from computer calculations, the research team will synthesize particles that can create uneven distributions of solute around their surfaces to generate self-propelled motion. Results from the project will be used in online course titled, "Creativity, Innovation, and Change."The utility of electrolyte diffusiophoresis as a propulsion mechanism is limited, especially at high-salt concentrations and in dielectric (apolar) media where many key applications lie. This project explores non-electrolyte diffusiophoresis, in which a particle generates local concentration gradients of non-electrolyte species to cause self-propulsion. The critical gap in knowledge is the connection between system chemistry and the speed of the self-propelled particle. This project will develop methods to calculate interaction energies based on rigorous descriptions of van der Waals attractions and hard-sphere repulsions between the particle and non-electrolyte solutes. Having the energies then enables the calculation of the chemical interaction parameter and the particle speed. The project will also construct self-propelled particles that incorporate appropriate ferrocene-containing polymers, gold nanoparticles, organometallic catalysts, and other species. The resulting motor chemistries will include attractive or repulsive moieties with the proper materials, sizes, and structures, to cause transport in a given set of solution conditions. From the known reaction kinetics, the concentration gradients will be calculated, and for the first time, the value of the interaction parameter will be measured. A measure of success includes observing non-electrolyte diffusiophoresis transport n three challenging test beds: aqueous with 5 M salt, physiological fluid, and hexane.