Exploring new frontiers of colloidal science: active colloids

活性胶体粒子是指能够在流体中自推进的微米/纳米粒子。它们的“游泳”能力使它们在新技术应用中变得有趣，从用于药物输送的货运颗粒到合成重现生物系统行为的模型悬浮液。它们也可能表现出类似于自然界常见的集体运动，从细菌群体中的成群现象到成群的鸟或鱼。 这些合成粒子有可能彻底改变医学上的许多常见程序。例如，它们逆流游泳的能力可以用来向伤口输送治疗药物以止血，或者它们可以通过胃肠道到达如果不进行侵入性手术就很难到达的地方。此外，活性胶体将被用作设计新的“活性”复合材料的积木。由于它们的构成元素(活性颗粒)的运动，这些新的复合材料将能够对外部刺激做出反应，并在飞行中改变其机械、热和电性能。 在这些独特可能性的推动下，该研究计划旨在(1)进一步发展活性胶体领域的基础知识，(2)开发活性胶体的独特性质，以基于活性胶体和复杂流体的组合生成新材料。 在我们的研究小组中，我们将合成活性胶体颗粒，研究它们在复杂流体中的动力学，以深入了解它们在生物流体(如粘液、唾液或血液，天生具有粘弹性)中的行为，并最终设计/开发新型多功能复合材料。我们的研究结果将有助于我们设计新的解决方案来控制活性胶体的运动方向，提高它们的游泳速度和效率。此外，将致力于完成目前触手可及的药物输送应用这一步骤。 最后，参与这项研究计划的人员将接受最先进技术的培训，他们将获得跨学科的科学知识，这将使他们成为加拿大和国际科学界的强大资产。这将使他们能够回应我们社会的科学和技术需求，并具体提出更好的解决方案，以改善我们的日常生活质量。

Active colloidal particles are micro/nano sized particles which are able to self-propel in fluids. Their ability to “swim” makes them interesting for new technological applications ranging from cargo particles for drug delivery to model suspensions to recreate synthetically the behaviour of biological systems. They may also display collective motion, similar to that commonly seen in nature, from swarming phenomena in bacterial colonies to flocks of birds or fish. These synthetic particles hold potential to revolutionize many common procedures applied in medicine. For example, their ability to swim against blood flow can be used to delivery therapeutics into wounds to halt hemorrhage or they can travel through the gastrointestinal tract and reach locations which are inherently difficult to hit without invasive surgeries. Furthermore, active colloids will be used as building blocks in designing new “active” composites. Thanks to the movement of their constitutive elements (the active particles), these new composites will be able to respond to external stimuli and change their mechanical, thermal and electrical properties on-the-fly. Motivated by these unique possibilities, this research program aims to (1) further develop fundamental knowledge in the field of active colloids and (2) exploit the unique properties of active colloids in generating new materials based on the combination of active colloids and complex fluids. In our research group, we will synthetize active colloidal particles, study their dynamics in complex fluids to gain insights into their behaviour in biological fluids (such as mucus, saliva or blood which are inherently viscoelastic) and finally design/develop new multi-functional composites. The results of our investigations will help us to engineer new solutions to control active colloids' direction of motion and improve their swimming speed and efficiency. Furthermore, a strong effort will be dedicated to completing the step towards drug-delivery applications that are currently within reach. Finally, the personnel involved in this research program will receive training on state-of-art technologies and they will acquire interdisciplinary scientific knowledge which will make them strong assets for the Canadian and International scientific community. This will enable them to respond to the scientific and technological needs of our society and to concretize better solutions to improve our daily quality of life.