TY - JOUR

T1 - Chronopotentiometric Evaluation of Ionization Degree and Dissociation Constant of Imidazolium-Based Ionic Liquid [C(6)Meim][NTf2] in Polymeric Plasticized Membranes

AU - Pokhvishcheva, Nadezhda V.

AU - Gigiadze, Elizaveta K.

AU - Kalinichev, Andrey V.

AU - Ievlev, Alexandr V.

AU - Tyutyukin, Konstantin V.

AU - Peshkova, Maria A.

N1 - Funding Information: Funding: This research was funded by the Russian Science Foundation, grant number 20‐73‐10033 Funding Information: This research was funded by the Russian Science Foundation, grant number 20?73?10033Authors acknowledge Chemical Analysis and Materials Research Centre of Research Park at SPBU and personally Yakov M. Grigoriev; and Magnetic Resonance Research Centre of Research Park at SPBU and personally Mikhail A. Vovk for carrying out NMR experiments. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2022/2

Y1 - 2022/2

N2 - Ionic liquids (ILs) have a wide variety of applications in modern electrochemistry due to their unique electrolytic properties. In particular, they are promising candidates as dopants for polymeric membranes in potentiometric sensors and liquid-junction free reference electrodes. However, the effective use of ILs requires a comprehensive understanding of their electrolytic behavior in the polymeric phase. We report here the exploration of the electrolytic and diffusion properties of IL 1-hexyl-3-methyl-1H-imidazol-3-ium bis[(trifluoromethyl)sulfonyl]amide ([C(6)Meim][NTf2]) in a poly(vinyl chloride) matrix. Chronopotentiometry is utilized to determine the concentration of charge carriers, ionic diffusion coefficients and apparent dissociation constant of [C(6)Meim][NTf2] in PVC membranes plasticized with a mixture of [C(6)Meim][NTf2] and bis(2-ethylhexyl) sebacate (DOS) over a wide range of IL concentrations. The diffusion properties of [C(6)Meim][NTf2] are confirmed by NMR-diffusometry. The non-monotonic electrolytic behavior of the IL in PVC-DOS matrix is described for the first time. A maximum ionization degree and diffusion coefficient is observed at 30 wt.% of IL in the plasticizing mixture. Thus, it is shown that by varying the flexible parameter of the IL to plasticizer ratio in the polymeric phase one can tune the electrolytic and transport properties of sensing PVC membranes.

AB - Ionic liquids (ILs) have a wide variety of applications in modern electrochemistry due to their unique electrolytic properties. In particular, they are promising candidates as dopants for polymeric membranes in potentiometric sensors and liquid-junction free reference electrodes. However, the effective use of ILs requires a comprehensive understanding of their electrolytic behavior in the polymeric phase. We report here the exploration of the electrolytic and diffusion properties of IL 1-hexyl-3-methyl-1H-imidazol-3-ium bis[(trifluoromethyl)sulfonyl]amide ([C(6)Meim][NTf2]) in a poly(vinyl chloride) matrix. Chronopotentiometry is utilized to determine the concentration of charge carriers, ionic diffusion coefficients and apparent dissociation constant of [C(6)Meim][NTf2] in PVC membranes plasticized with a mixture of [C(6)Meim][NTf2] and bis(2-ethylhexyl) sebacate (DOS) over a wide range of IL concentrations. The diffusion properties of [C(6)Meim][NTf2] are confirmed by NMR-diffusometry. The non-monotonic electrolytic behavior of the IL in PVC-DOS matrix is described for the first time. A maximum ionization degree and diffusion coefficient is observed at 30 wt.% of IL in the plasticizing mixture. Thus, it is shown that by varying the flexible parameter of the IL to plasticizer ratio in the polymeric phase one can tune the electrolytic and transport properties of sensing PVC membranes.

KW - polymeric membranes

KW - ionic liquids

KW - diffusion coefficients

KW - plasticizer

KW - ion-selective sensors

KW - ionization degree

KW - ion pairs

KW - polarity

KW - chronopotentiometry

KW - REFERENCE ELECTRODES

KW - CHEMICAL SENSORS

KW - JUNCTION

KW - ASSOCIATION

KW - IMPURITIES

KW - SOLUBILITY

KW - DESIGN

KW - CARBON

KW - Polarity

KW - Ion‐selective sensors

KW - Diffusion coefficients

KW - Polymeric membranes

KW - Ion pairs

KW - Plasticizer

KW - Ionic liquids

KW - Chronopotentiometry

KW - Ionization degree

UR - http://www.scopus.com/inward/record.url?scp=85123045951&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/42dbdedb-2d37-362d-a218-ff90d75bdd64/

U2 - 10.3390/membranes12020130

DO - 10.3390/membranes12020130

M3 - статья

VL - 12

JO - Membranes

JF - Membranes

SN - 2077-0375

IS - 2

M1 - 130

ER -