Department of Chemistry, Imperial College London, London SW7 2AZ, UK.
Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.
Faraday Discuss. 2013;165:343-56. doi: 10.1039/c3fd00041a.
The viscosity of atmospheric aerosol particles affects a number of key physical and chemical particle properties, such as composition and reactivity. However, determination of the microscopic viscosity of aerosol particles is a non-trivial task. We report a new method of imaging viscosity in a variety of model aerosol systems, based on a fluorescence lifetime determination of viscosity-sensitive fluorophores termed molecular rotors. We report the viscosity changes associated with the relative humidity dependent hygroscopicity of NaCI and sucrose aerosols, as well as reaction dependent changes in viscosity during ozonolysis of oleic acid aerosols. The Fluorescence Lifetime Imaging Microscopy (FLIM) of molecular rotors shows great promise in understanding important fundamental aerosol properties, which can be both time-dependent and spatially variable through the aerosol particle.
大气气溶胶粒子的粘度会影响许多关键的物理和化学粒子性质，例如组成和反应性。然而，气溶胶粒子的微观粘度的测定是一项复杂的任务。我们报告了一种新的方法，可以通过称为分子转子的对粘度敏感的荧光团的荧光寿命测定来成像各种模型气溶胶系统中的粘度。我们报告了与 NaCl 和蔗糖气溶胶的相对湿度依赖性吸湿性以及油酸气溶胶的臭氧分解过程中粘度随反应变化相关的粘度变化。分子转子的荧光寿命成像显微镜（FLIM）在理解重要的基本气溶胶性质方面具有很大的潜力，这些性质可以通过气溶胶粒子随时间和空间变化。
