In-depth investigation on THz spectrum of 1-butyl-3-methylimidazolium dicyanamide spreading on graphene surface by computational calculation

摘要: Abstract Understanding dynamic change of ionic liquid (IL) THz spectrum under certain conditions is a real challenge. Herein, through spreading 1-butyl-3-methylimidazolium dicyanamide ([Bmim][DCA]) nanodroplet on graphene surface, [Bmim][DCA] in the range from 30 to 300 cm−1 probed by computational calculation at 300 K. Analyzing calculated spectra it can be found that vibrational bands 49.95 (cation-anion bend), 216.45 cm−1 (rocking CH3 alkyl chain) show 16.65 cm−1 blue shift as time increases 0 5 ns and further blue-shift 10 20 ns, while band 266.40 cm−1 (bend methyl) only blue-shifts 20 ns. The underlying mechanism revealed stronger adsorbed layer forming graphene-IL interface which enhances hydrogen bonds between cations anions, constrains torsion out-of-plane bend group chain methyl respectively. findings described here represent an important step developing comprehensive understanding manipulation IL surface.