Physical, Chemical and Electromagnetic Wave-induced Processes in Microdroplets

摘要CTS 96-18283 拟议的研究的目标是检查成核，光化学和化学反应的均匀和分层的微滴。实验将进行单液滴悬浮在电动平衡和高度单分散液滴产生的振动孔气雾剂发生器。 基于共振的弹性和非弹性光散射技术（即，强度峰值）将用于确定均匀和分层液滴的尺寸和折射率。 液-固相分离方法（即，成核）来理解控制固体颗粒结构的机制，并且具有微滴的分层液滴的形成表明，在共振条件下微滴中的光化学反应速率显著增强。 理论分析的结果将进行测试与实验数据的光照射的波长对应于共振的微滴中发生的光化学反应。 在含有MnSO 4的水溶液液滴中氧化SO2的先前实验表明，可以获得反应动力学的准确数据。 在这个项目中，用于生成固体颗粒的液滴-蒸气反应将被检查，以确定是否可以通过液滴相反应改变的并联-串联反应中的产物之一的选择性。最后，核心液滴涂有惰性不混溶层和气相反应物之间的反应将进行理论和实验研究，以了解气体层的界面面积和扩散阻力的层上的整体反应速率的影响。

ABSTRACT CTS 96-18283 The objectives of the proposed research are to examine nucleation, photochemical and chemical reactions in homogeneous and layered microdroplets. Experiments will be conducted on single droplets suspended in an electrodynamic balance and on highly monodisperse droplets generated by a vibrating orifice aerosol generator. Elastic and inelastic light scattering techniques, based on resonances (i.e., intensity peaks) observes in scattered light, will be used to determine size and refractive indices of homogeneous and layered droplets. Liquid-solid phase separation processes (i.e., nucleation) in microdroplets will be examined to understand the mechanisms that control the structures of solid particles and the formation of layered droplets with microdroplets suggests that photochemical reaction rates in microdroplets under resonance conditions enhance significantly. The results of the theoretical analysis will be tested with experimental data on photochemical reactions occurring in microdroplets illuminated by light whose wavelength corresponds to a resonance. Prior experiments on oxidation of SO2 in aqueous solution droplets containing MnSO4 show that accurate data on reaction kinetics can be obtained. In this project droplet-vapor reactions used for generation of solid particles will be examined to determine whether the selectivity of one of the products in a parallel-series reaction can be altered by the droplet phase reaction. Finally, reactions between core droplets coated with inert immiscible layers and gas phase reactants will be examined theoretically and experimentally to understand the effects of the gas-layer interfacial area and diffusional resistance of the layer on the overall reaction rate.