Study on size separation and structural analysis of hydrate clusters and their interactions with solid surfaces

2014 Fiscal Year Final Research Report

• Project/Area Number: 24360010
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Applied materials science/Crystal engineering
• Research Institution: Kyoto University
• Principal Investigator: TAKAOKA Gikan 京都大学, 工学(系)研究科(研究院), 教授 (90135525)
• Co-Investigator(Kenkyū-buntansha): RYUTO Hiromichi 京都大学, 大学院工学研究科, 講師 (20392178) ; TAKEUCHI Mitsuaki 京都大学, 大学院工学研究科, 助教 (10552656)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 水クラスター / 水和クラスター / イオンビーム / クラスターサイズ / サイズ分析 / 構造解析 / メタン / 二酸化炭素

Outline of Final Research Achievements

The clusters such as CO2 and CH4 gas-hydrate clusters were produced by adiabatic expansion. The size distribution of CH4 gas-hydrate clusters was similar to that of H2O clusters. On the other hand, the size distribution of CO2 gas-hydrate clusters was different from that of H2O clusters, and the size of CO2 gas-hydrate clusters was larger than that of H2O clusters. In addition,the HEED patterns for H2O and CO2 clusters were measured. H2O clusters represented the diamond structure of crystal ice. The network structure of hydrogen bonds was formed in the H2O cluster. For CO2 clusters, the FCC structure of dry ice was observed, and the cluster temperature was less than 200 K.
Furthermore, we investigated the interaction of cluster ions with solid surface atoms. CO2 and CH4 gas-hydrate cluster ions were accelerated toward metal substrates. The surface temperature of cluster-impact area increased, resulting in enhancement of the chemical reaction between H2O and gas molecules.

Free Research Field

工学