Relationships between center atom species (N, P) and ionic conductivity, viscosity, density, self-diffusion coefficient of quaternary cation room-temperature ionic liquids.
The physicochemical properties (ionic conductivity, viscosity, density, and self-diffusion coefficient) of tri-n-ethylpentylphosphonium bis(trifluoromethanesulfonyl)amide (TEPP-TFSA) ionic liquid were compared with those of tri-n-ethylpentylammonium bis(trifluoromethanesulfonyl)amide (TEPA-TFSA). Compared with the TEPA-TFSA ionic liquid, the density and viscosity of the phosphorus ionic liquid are lower, although the ionic conductivity and self-diffusion coefficient are higher. The molar conductivities were compared for the values obtained by the electrochemical impedance method (electrochemical conductivity) and the calculated from the pulsed-gradient spin-echo nuclear magnetic resonance method (diffusive conductivity). The comparison shows that active ionic ratios of the TEPP-TFSA ionic liquid were smaller than those of the TEPA-TFSA ionic liquid in the whole temperature, regardless of the lower viscosity of the TEPP-TFSA ionic liquid, and results with high precision were obtained using Walden's law.
Seki
Shiro
S
Materials Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1, Iwado-kita, Komae, Tokyo, 201-8511, Japan. s-seki@criepi.denken.or.jp
Hayamizu
Kikuko
K
Tsuzuki
Seiji
S
Fujii
Kenta
K
Umebayashi
Yasuhiro
Y
Mitsugi
Takushi
T
Kobayashi
Takeshi
T
Ohno
Yasutaka
Y
Kobayashi
Yo
Y
Mita
Yuichi
Y
Miyashiro
Hajime
H
Ishiguro
Shin-ichi
S