Active Particles in Colloidal Liquid

胶体液体中的活性粒子

• 批准号: 1950179
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1950179
• 关键词: Active; Particles; Colloidal; Liquid

Active particles have been an area of great interest in the past decade. Not only do their motions and behaviours provide interesting ways to develop the scienceof non-equilibrium dynamics, they are also relevant in the study of animate objects on the macroscale; such as birds, crowds and bacteria. Despite having been at the front of recent colloidal research very little is know about the specifics of their interactions with their environments. There are many examples of experimental systems that not only express the typical characteristics of active motion, but also have their own peculiar facets. I intend on investigating how certain active particles behave and interact with a system of colloidal rods. Lachlan would like to both discover more about how the colloidal liquid crystals affects the active particles and how in turn the liquid crystal is affected. To achieve a colloidal liquid crystal Lachlan will use rod shaped silica particles and the FD virus (a virus also shaped as a rod). In the silica system he will use other active silica particles half coated in specific metals, both rods and spheres, and propel them using the well known AC current method or with the catalysed decomposition of hydrogen peroxide. For the FD virus liquid crystal Lachlan intend on using a certain strain of the Bacillus subtilis bacteria. Specifically it would be interesting how the aspect ratio of the colloids affect the system as well as the size ratio between the liquid crystal blocks and the active particles. Using different shapes of active particles may prove interesting to show how the excluded volume of the liquid crystal, caused by a miss-match between the active and passive particles, may thermodynamically alter their behaviour. Although in previous work the three active systems have been mostly categorised and cases have been observed where the presence of a molecular liquid crystal has affected the motion of active particles, in these cases the size of the blocks of the liquid crystal has been several orders of magnitude smaller than the size of the active matter. Therefore, investigating the region where the size of the blocks of the liquid crystal is similar to the active component of the system is new and may provide new complex phenomena in the interplay of the particles. It is hoped to achieve, with this project, a furthered understanding of not only the specific system that Lachlan will be working with but to bring that knowledge and be able to apply it to a broader scope of physical phenomena. Cells, for example, are a complex mix of microscale or nanoscale structures which can interact to form pseudo liquid crystals and therefore studying the interaction of active particles in similar environments could give insights to intracellular transport or even how to deal with viral or bacterial infections. At this stage, the field of active particle research has been very successful in providing theoretical simulations and the predictions of certain useful phenomena and we hope to provide some experimental grounding to them. Furthermore, in the long term it may be possible to create devices or materials with specific tunable functions. The most obvious use for synthetic active particles is to make a targeted drug delivery system.

在过去的十年中，活性粒子一直是人们非常感兴趣的领域。它们的运动和行为不仅为发展非平衡动力学科学提供了有趣的方法，它们还与宏观尺度上的生物研究有关;例如鸟类，人群和细菌。尽管处于最近胶体研究的前沿，但对它们与环境相互作用的细节知之甚少。有许多实验系统的例子，不仅表达了主动运动的典型特征，而且有自己独特的方面。我打算研究某些活性粒子的行为以及与胶体棒系统的相互作用。Lachlan希望更多地了解胶体液晶如何影响活性颗粒，以及液晶如何反过来受到影响。为了实现胶体液晶，Lachlan将使用棒状二氧化硅颗粒和FD病毒（一种也是棒状的病毒）。在二氧化硅系统中，他将使用其他活性二氧化硅颗粒，半涂在特定的金属上，包括棒和球，并使用众所周知的AC电流方法或过氧化氢的催化分解来推动它们。对于FD病毒的液晶Lachlan打算使用一定的枯草芽孢杆菌菌株的细菌。具体而言，胶体的纵横比如何影响系统以及液晶块和活性颗粒之间的尺寸比将是有趣的。使用不同形状的活性颗粒可以证明有趣的是，显示由活性颗粒和无源颗粒之间的不匹配引起的液晶的排除体积如何可以在物理上改变它们的行为。虽然在以前的工作中，这三种活性系统已被大部分分类，并已观察到分子液晶的存在影响了活性颗粒的运动的情况下，在这些情况下，液晶块的大小已经比活性物质的大小小了几个数量级。因此，研究液晶块的尺寸与系统的活性组分相似的区域是新的，并且可以提供颗粒相互作用中的新的复杂现象。希望通过这个项目，不仅能够进一步了解Lachlan将使用的特定系统，而且能够将这些知识应用于更广泛的物理现象。例如，细胞是微米级或纳米级结构的复杂混合物，它们可以相互作用形成伪液晶，因此研究活性颗粒在类似环境中的相互作用可以深入了解细胞内运输甚至如何处理病毒或细菌感染。现阶段，活跃粒子研究领域在提供理论模拟和预测某些有用现象方面非常成功，我们希望为它们提供一些实验基础。此外，从长远来看，可能会产生具有特定可调功能的设备或材料。合成活性颗粒最明显的用途是制造靶向药物递送系统。