Thermal generation of aerosols from liquid mixtures usually requires their fast evaporation, to create supersaturated vapors, and their subsequent cooling to trigger homogeneous nucleation process resulting in the aerosol formation. The processes of nuclei formation and its subsequent growth by condensation are studied since years in the laminar flow diffusion (or shock tube expansion) chambers. The goal of these studies is to predict nucleation rates mostly for the binary or rather rarely for ternary mixtures. Since past decades emerged discrepancies between the classical nucleation theory outcomes and generated experimental data remain still as subject of investigations and lead to corrections and re-formulations of the theoretical frameworks. In particular, the nucleation of multispecies mixtures is unexplored as depending on the physico-chemical properties of major bulk carrier components as well as low mass-fraction present species. The aim of this proposal is to investigate formation of thermally generated aerosols from multispecies mixtures with the use of neutron scattering techniques. Seminal work using neutron scattering in aerosol studies [1], performed more than two decades ago, opened new avenues in indirect studies of aerosol particles dynamics, species phase partitioning and related chemistry. By application of in situ engineered experimental setup and using capillary aerosol generator [2] as a reliable source of aerosol generation, the subtle dynamics and formation of aerosol will be studied by the application of small angle neutron scattering technique with contrast variation. The studies starting with single aerosol former will be extended to multispecies mixtures. Influence of mixture components on the aerosol formation and measured aerosol physical and chemical characteristics will be investigated in the narrow aerosol formation zone close to the capillary outlet. Obtained results may deliver verification data for recently performed numerical simulations for aerosol formation in the geometry of the capillary aerosol generator [3] by using extension of the classical nucleation theory. Designed parametric experimental studies will aim to deliver better understanding on the influence of the mixture properties and external conditions for delivering aerosols with controlled properties.

[1] Small Angle Neutron Scattering from Nanodroplet Aerosols, Wyslouzil, B.E.  and Cheung, J.L. and Wilemski, G. and Strey, R. Phys. Rev. Lett. 79, 431, 1997

[2] Effect of energy on propylene glycol aerosols using the capillary aerosol generator. Shen, X and Hindle, M and Byron, P.R., Int J Pharm., 4, 275(1-2), 2004

[3] AeroSolved: Computational fluid dynamics modeling of multispecies aerosol flows with sectional and moment methods, Lucci, F. and Frederix, E. and Kuczaj, A.K., J. Aerosol Science, 159, 2022