Studies Pertaining to Aerosol Formation: Nucleation Phenomena, Charging Mechanisms and Growth.

摘要

In recent years there has been a rekindling of interest in the field of aerosol science, with emphasis on studies of the properties of small particles and in the mechanisms by which they are formed and subsequently grow. This has been brought on partly by the advent of new experimental techniques which enable an investigation of the molecular properties of small aggregates, termed nucleation embryos, which give new insight into such fundamental problems as phase transitions, the formation, structure and reactivity of surfaces, and the nature and stability of the aerosol state. In terms of applied areas, such studies have a direct bearing on the fields of obscuration science, combustion research, catalysis, and the atmospheric sciences, to mention just a few. The research conducted during the grant period was addressed to three general areas: (1) Investigations of the energetics and structure of both ion and neutral-molecular complexes involving species which are important prenucleation embryos in both the natural and perturbed atmosphere; (2) Studies of the dynamics of cluster growth in expanding flows and concurrent assessments of the applicability of current theoretical models in assessing the energy barrier to nucleation; and (3) The development of techniques for determining the mechanisms of aerosol charging and related studies of cluster photostability.