Structure and properties of water confined in the nano-surface and space of carbon nanotube

2014 Fiscal Year Final Research Report

• Project/Area Number: 24310094
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Nanomaterials/Nanobioscience
• Research Institution: Tokyo University of Science
• Principal Investigator: HOMMA Yoshikazu 東京理科大学, 理学部, 教授 (30385512)
• Co-Investigator(Kenkyū-buntansha): YAMAMOTO Takahiro 東京理科大学, 工学部, 講師 (30408695) ; OKADA Susumu 筑波大学, 大学院数理物質科学研究科, 教授 (70302388) ; CHIASHI Shohei 東京大学, 大学院工学系研究科, 講師 (50434022)
• Co-Investigator(Renkei-kenkyūsha): KATO Hiroki 東京理科大学, 理学部, 助教 (70579846)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: カーボンナノチューブ / 水 / 相図 / ナノ空間

Outline of Final Research Achievements

We have investigated the interaction of single-walled carbon nanotube (SWNT) and water molecules in the nanoscale using singly suspended SWNTs as a controlled nanospace. Based on optical measurements of individual SWNTs in water vapor together with theoretical simulations, we found that water molecules form a stable adsorption layer of 2 ML thickness on the outer surface of SWNT. This adsorption layer shows hydrophobicity because of the closed hydrogen bonding within two layers, and increases the radial breathing mode frequency in the Raman spectrum of SWNT. We also succeeded in controlling the phase of water confined in the inner space of SWNT with the temperature and water vapor pressure. It is suggested that phase separation (empty or gas phase and condensed phase) of water molecules occurs during the encapsulation process.

Free Research Field

ナノ構造物理学