TY - JOUR

T1 - Nanocage formation and structural anomalies in imidazolium ionic liquid glasses governed by alkyl chains of cations

AU - Bakulina, Olga D.

AU - Ivanov, Mikhail Yu

AU - Prikhod'ko, Sergey A.

AU - Pylaeva, Svetlana

AU - Zaytseva, Irina V.

AU - Surovtsev, Nikolay V.

AU - Adonin, Nicolay Yu

AU - Fedin, Matvey V.

N1 - Russian Science Foundation № 19-13-00071.

PY - 2020/10/14

Y1 - 2020/10/14

N2 - Intriguing nanostructuring anomalies have been recently observed in imidazolium ionic liquids (ILs) near their glass transition points, where local density around a nanocaged solute progressively grows up with temperature. Herewith, we for the first time demonstrate experimentally and theoretically, that these anomalies are governed by alkyl chains of cations and crucially depend on their length. Electron Paramagnetic Resonance (EPR) spectroscopy on a series of ILs [Cnmim]BF4 (n = 0-12) shows that only the chains with n = 3-10 favor anomaly. Moreover, remarkable even vs. odd n peculiarities were systematically observed. Finally, similar anomaly was for the first time observed for a non-IL glass of dibutyl phthalate, which structurally mimics cations of imidazolium ILs. Therefore, such anomalous density behavior in a glassy state nanocage goes far beyond ILs and proves to be a more general phenomenon, which can be structurally tuned and rationally adjusted for various potential applications in nanoscale materials.

AB - Intriguing nanostructuring anomalies have been recently observed in imidazolium ionic liquids (ILs) near their glass transition points, where local density around a nanocaged solute progressively grows up with temperature. Herewith, we for the first time demonstrate experimentally and theoretically, that these anomalies are governed by alkyl chains of cations and crucially depend on their length. Electron Paramagnetic Resonance (EPR) spectroscopy on a series of ILs [Cnmim]BF4 (n = 0-12) shows that only the chains with n = 3-10 favor anomaly. Moreover, remarkable even vs. odd n peculiarities were systematically observed. Finally, similar anomaly was for the first time observed for a non-IL glass of dibutyl phthalate, which structurally mimics cations of imidazolium ILs. Therefore, such anomalous density behavior in a glassy state nanocage goes far beyond ILs and proves to be a more general phenomenon, which can be structurally tuned and rationally adjusted for various potential applications in nanoscale materials.

KW - NANOSTRUCTURAL ORGANIZATION

KW - SPIN PROBES

KW - DYNAMICS

KW - SOLVENTS

KW - LENGTH

KW - EPR

KW - HETEROGENEITIES

KW - VISCOSITY

KW - BEHAVIOR

KW - SALTS

UR - http://www.scopus.com/inward/record.url?scp=85092741243&partnerID=8YFLogxK

U2 - 10.1039/d0nr06065h

DO - 10.1039/d0nr06065h

M3 - Article

C2 - 32996529

AN - SCOPUS:85092741243

VL - 12

SP - 19982

EP - 19991

JO - Nanoscale

JF - Nanoscale

SN - 2040-3364

IS - 38

ER -