Study on reaction control by pressure change at the supercritical carbon dioxide-water interface

2016 Fiscal Year Final Research Report

• Project/Area Number: 26410143
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Analytical chemistry
• Research Institution: Ibaraki University
• Principal Investigator: Ohashi Akira 茨城大学, 理学部, 准教授 (50344833)
• Co-Investigator(Renkei-kenkyūsha): KIM Haeng-Boo 茨城大学, 理学部, 教授 (40186367) ; YAMAGUCHI Akira 茨城大学, 理学部, 教授 (10359531)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 超臨界二酸化炭素 / 界面 / 吸着 / 会合

Outline of Final Research Achievements

A reflection spectrometric device was developed to directly measure adsorbates at SC-CO2-water interface. The aggregation of diprotonated anionic porphyrin (H4tpps2－) at the positively charged SC-CO2-water interface, prepared by adsorption by cationic surfactants, was studied using this device. Dependence of the reflection spectra on cationic surfactant concentration and CO2 pressure were investigated, and the interfacial cationic surfactant concentration was found to cause changes in the interfacial H4tpps2－ species present. Increasing the CO2 pressure changed the interfacial species from the H4tpps2－ monomer to the H4tpps2－ J-aggregate because the interfacial cationic surfactant concentration increased as the pressure increased. This suggests that the interfacial chemical species can be changed by controlling the pressure and temperature of the SC-CO2. This is the first report of direct measurements of the chemical species at the SC-CO2-water interface.

Free Research Field

分析化学