Extremely high frequency dynamics study of polymer solutions using THz spectroscopic techniques

2016 Fiscal Year Final Research Report

• Project/Area Number: 26288055
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Polymer chemistry
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Shikata Toshiyuki 東京農工大学, (連合)農学研究科(研究院), 教授 (10178858)
• Co-Investigator(Kenkyū-buntansha): 田中 文彦 京都大学, 工学(系)研究科(研究院), 名誉教授 (50107695)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: テラヘルツ分光 / 水溶性高分子 / 親水性基 / 中間親水性基 / 誘電スペクトル / 水和 / 水素結合

Outline of Final Research Achievements

We established a broadband dielectric spectrum measuring system covering a frequency range from 1 M to 3 GHz. The obtained dielectric spectra of aqueous solution of hydrophilic polymers revealed that the relaxation mode assigned to dangling water hydroxy groups without forming hydrogen bonding to other water molecules decreased with increasing concentration. On the other hand, a relaxation mode was newly found, and its intensity increased with increasing the concentration. These proposed that the (hydrophilic) hydration is resulted from hydrogen bond formation between a dangling water hydroxy group and a hydrophilic one.
Dielectric spectra demonstrated that water hydroxyl groups adjacent nitro and cyano groups do not form hydrogen bonds to the groups, but cause only dipole-dipole interactions, then they become dangling ones. Since nitro and cyano groups possess intermediate characteristics between hydrophilic and hydrophobic groups, they are classified into hydroneutral groups.

Free Research Field

高分子物理化学