TY - JOUR
T1 - Investigation of Dynamic Behavior of Confined Ionic Liquid [BMIM]+[TCM]− in Silica Material SBA-15 Using NMR
AU - Gkoura, Lydia
AU - Panopoulos, Nikolaos
AU - Karagianni, Marina
AU - Romanos, George
AU - Chatzichristos, Aris
AU - Papavassiliou, George
AU - Hassan, Jamal
AU - Fardis, Michael
N1 - Publisher Copyright:
© 2023 by the authors.
PY - 2023/4
Y1 - 2023/4
N2 - The molecular dynamics of 1-butyl-3-methyl imidazolium tricyanomethanide ionic liquid [BMIM]+[TCM]− confined in SBA-15 mesoporous silica were examined using 1H NMR spin-lattice (T1) relaxation and diffusion measurements. An extensive temperature range (100 K–400 K) was considered in order to study both the liquid and glassy states. The hydrogen dynamics in the two states and the self-diffusion coefficients of the cation [BMIM]+ above the glass transition temperature were extracted from the experimental data. The results were then compared to the corresponding bulk substance. The effects of confinement on the dynamic properties of the ionic liquid clearly manifest themselves in both temperature regimes. In the high-temperature liquid state, the mobility of the confined cations reduces significantly compared to the bulk; interestingly, confinement drives the ionic liquid to the glassy state at a higher temperature Tg than the bulk ionic liquid, whereas an unusual T1 temperature dependence is observed in the high-temperature regime, assigned to the interaction of the ionic liquid with the silica-OH species.
AB - The molecular dynamics of 1-butyl-3-methyl imidazolium tricyanomethanide ionic liquid [BMIM]+[TCM]− confined in SBA-15 mesoporous silica were examined using 1H NMR spin-lattice (T1) relaxation and diffusion measurements. An extensive temperature range (100 K–400 K) was considered in order to study both the liquid and glassy states. The hydrogen dynamics in the two states and the self-diffusion coefficients of the cation [BMIM]+ above the glass transition temperature were extracted from the experimental data. The results were then compared to the corresponding bulk substance. The effects of confinement on the dynamic properties of the ionic liquid clearly manifest themselves in both temperature regimes. In the high-temperature liquid state, the mobility of the confined cations reduces significantly compared to the bulk; interestingly, confinement drives the ionic liquid to the glassy state at a higher temperature Tg than the bulk ionic liquid, whereas an unusual T1 temperature dependence is observed in the high-temperature regime, assigned to the interaction of the ionic liquid with the silica-OH species.
KW - confined ionic liquids
KW - mesoporous silica SBA-15
KW - NMR
KW - relaxation and diffusion
UR - http://www.scopus.com/inward/record.url?scp=85152317171&partnerID=8YFLogxK
U2 - 10.3390/ijms24076739
DO - 10.3390/ijms24076739
M3 - Article
C2 - 37047711
AN - SCOPUS:85152317171
SN - 1661-6596
VL - 24
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 7
M1 - 6739
ER -