Dynamic analysis of evaporation of charged nanodroplets and formed ions

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05189
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 27010:Transport phenomena and unit operations-related
• Research Institution: University of Occupational and Environmental Health, Japan
• Principal Investigator: Higashi Hidenori 産業医科大学, 産業生態科学研究所, 教授 (40294889)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 帯電液滴 / 静電噴霧 / 蒸発 / イオン / ナノ粒子 / 荷電

Outline of Final Research Achievements

In the present work, we have tried to elucidate the phenomenon by mutually utilizing the knowledge obtained from (1) experiments, (2) theory, and (3) molecular simulations, aiming to obtain guidelines for the optimal design of various equipment using the electrostatic atomization method. Then, in order to optimize the operating conditions, we have deepen the science of the charged droplet evaporation process. Using the information obtained from each method, we analyzed the evaporation and splitting processes of the generated multiply charged droplets, the formation process of ions and nanoparticles generated by the evaporation and splitting processes, and the morphology and dynamic behavior (such as electrical mobility) of the generated ions. We attempted to construct a universal theory linking molecules and particles by considering the behavior of droplets at small times from theoretical calculations and simulations, and the effects of droplet deformation from experiments.

Free Research Field

化学工学、エアロゾル科学技術、労働衛生工学

Academic Significance and Societal Importance of the Research Achievements

静電噴霧法は、質量分析器におけるイオン化装置やインクジェットプリンタ、あるいは農薬散布等に応用されている。静電噴霧法により生成した多価帯電液滴は、蒸発、Rayleigh分裂、イオン放出等の過程を経て、単一分子イオンやナノ粒子を生成する。本研究により生成する多価帯電液滴の蒸発・分裂過程のダイナミクスとそれに伴い発生するイオンやナノ粒子の生成過程、生成イオンの動態解析、つまり、より実際の現象に則した解析が可能となり、多価帯電液滴の効率的な搬送および生成イオンとナノ粒子からの機能発現の制御および帯電液滴の蒸発・分裂過程の定量的な理論的考察が可能となり、装置および操作条件の最適化につながる。