[16a-Z30-1~11] 17.1 Carbon nanotubes & other nanocarbon materials

[16a-Z30-6] Simulation of viscosity of ionic liquid under high shear rate conditions

〇Tatsuya Yamada¹, Hiroshi Ushiyama¹, Syogo Tejima¹, Jun-ichi Fujita² (1.RIST, 2.Univ. of Tsukuba)

Keywords:bucky gel, ionic liquid, viscoelasticity

Bucky gels consisting of carbon nanotubes and Ionic Liquid (IL) are interesting in the point of view of the development of shock resistant material. To unravel the molecular mechanism of the characteristic viscoelastic properties of bucky gels, we calculated the dependence of the viscosity of IL (1-Ethyl-3-methylimidazolium Tetrafluoroborate) on the shear rate under high shear rate conditions (10⁸-10¹³ [1/s]) using all-atom molecular dynamics simulations. The viscosity was evaluated from shear rate and the shear stress generated by the continuous/vibrational shear deformation of the IL system. In the large shear rate region (>10⁹ [1/s]) IL showed a remarkable shear thinning behavior, which was considerably declined when electrostatic interactions were not taken into account for the simulations. We concluded that the shear thinning is caused by the reduction of the electrostatic part of the viscous flow activation energy that is responsible for the large viscosity of IL.