Evaporative Drying of Droplets and the Formation of Micro-structured and Functional Particles

液滴的干燥是一个复杂的过程，在液相内发生了丰富的动力学过程。这些内部过程的效果是改变干燥后形成的颗粒中材料的分布。这些过程在广泛的应用中非常重要，从形成功能化和微结构颗粒的喷雾干燥过程，到作物喷洒，再到吸入疗法中颗粒的动力学。在这个项目中，我们将使用一系列独特的单颗粒实验工具来探索空气中孤立液滴的干燥动力学。特别是，测量将使用电动天平直接探测干燥过程中液滴随时间演变的大小和形态，时间分辨率高达10ms。液滴的稳定平衡粘度和表面张力将使用气溶胶光学镊子随液滴组成的不同而变化。我们将试图了解液滴是如何干燥的，并提供一种量化的方法来测量、预测和解释液滴蒸发的动力学。例如，我们将解决这样的问题，如何时获得固体粒子或中空粒子，均匀粒子或有壳层的粒子？当形成时，颗粒是结晶的还是无定形的，不同的成分是混合的还是分离的？

The drying of liquid droplets is a complex process with a wealth of dynamics occurring inside the liquid phase. The effect of these internal processes is to change the distribution of materials in the particle that is formed after drying. These processes are important in a wide range of applications from spray drying processes that form functionalised and micro-structured particles, crop spraying and to the dynamics of particles during inhalation therapies. In this project we will explore the drying kinetics of isolated droplets in air using a range of unique single particle experimental tools. In particular, measurements will use an electrodynamic balance to directly probe the time-evolving size and morphology of droplets during drying with time-resolution as high as 10 ms. The steady equilibrium viscosity and surface tensions of droplets will be interrogated with varying droplet composition using aerosol optical tweezers. We will seek to understand how droplets dry and provide a quantitative approach to measure, predict and interpret the dynamics of droplet evaporation. For example, we will address questions such as when do you get a solid particle or a hollow particle, a uniform particle or one with shells? When formed, are the particles crystalline or amorphous, are different components mixed or separated?