Development of in situ structure analysis of single droplet levitaed in air and application to aerosol reactions

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K05551
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 34020:Analytical chemistry-related
• Research Institution: Fukuoka University
• Principal Investigator: Yamaguchi Toshio 福岡大学, 公私立大学の部局等, 研究特任教授 (70158111)
• Co-Investigator(Kenkyū-buntansha): 吉田 亨次 福岡大学, 理学部, 准教授 (00309890)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: エアロゾル液滴 / 溶液構造 / ラマン散乱 / イオン溶媒和 / 超音波浮揚 / 過飽和 / イオン会合 / X線散乱

Outline of Final Research Achievements

Raman scattering and synchrotron X-ray scattering methods of liquid droplets with diameters of 600micron to 1mm levitated in the air ultrasonically have been developed. From Raman scattering measurements of droplets of magnesium nitrate, magnesium sulfate, and acetic acid aqueous solutions, it was clarified that the concentrations of the droplets were in a supersaturated state several times higher than that of the bulk. The precipitated crystals were identified by observation of the crystallization process from droplets. The droplet X-ray scattering data were analyzed by EPSR calculations to determine the three-dimensional structure of the ionic solvation/association, and solvent water. A low-temperature chamber capable of measuring up to 243 K was constructed, and the three-dimensional structure of ionic solvation, association, and solvent water in the supercooled state of each droplet of magnesium sulfate aqueous solution and ethylene glycol-water mixed solution was clarified.

Free Research Field

溶液化学

Academic Significance and Societal Importance of the Research Achievements

本研究では超音波浮揚法により空気中に浮揚させた1mmサイズの単一液滴のラマン散乱とX線散乱法を開発した。マイクロL単位の微小体積を対象とするので希少タンパク質や高価な溶液構造解析に適用できる。セルフリーのために溶液の過飽和・過冷却現象や、融解・結晶化現象の構造を決定できる。液滴にオゾンガスなどを反応させることにより、雲中のエアロゾル反応を構造化学に研究できる。本手法は、液滴のミクロ構造と物性を明らかにすることにより、分析化学、物理化学、地球化学、生物化学、大気化学における種々の化学プロセスを3次元構造から解明できる。地球温暖化などのエアロゾル由来の気候変動を研究する基礎的指針を提供する。