TY - JOUR

T1 - Densities, refractive indices and conductivities of aqueous [Cnmim][Pro] solutions (n = 4, 8, 12); micellization and the capillary electrophoresis data at 298.15 K

AU - Alopina, E.

AU - Dobryakov, Yuri G.

AU - Safonova, E.

AU - Smirnova, N.

AU - Kolobova, E.

AU - Kartsova, L.

N1 - cited By 0

PY - 2018/5/5

Y1 - 2018/5/5

N2 - The densities of aqueous solutions of amino acid ionic liquids (AAILs) based on 1-alkyl-3-methylimidazolium cations and L-prolinate anions [C(n)mim][Pro] (n = 4, 8, 12) in the concentration range 0-97 wt% were measured at several constant temperatures in the range 293.15-318.15 +/- 0.05 K. It has been found that in the range of high AAIL concentrations the dependence of the density values on the AAIL mole fraction for binary water+[C(n)mim] [Pro] solutions is nonlinear. The refractive indices of aqueous solutions of these AAILs in the concentration range 0-97 wt % and the electrical conductivities of aqueous [C(n)mim][Pro] (n = 8, 12) solutions were measured at temperature 298.15K. Critical micelle concentrations (cmc) of AAILs, degree of counterion binding (beta), standard Gibbs energy of micellization (Delta G degrees(m)) for them were estimated from the experimental data. The dependences of the cmc, beta and Delta G degrees(m), on the length of the alkyl chain of the cations were discussed. The synthesized AAILs [C(n)mim] [Pro] were examined as chiral selectors for the separation of D,L-tryptophan and D,L-tyrosine enantiomers using the ligand exchange capillary electrophoresis. The highest resolution factors Rs are observed in the case of [C(4)mim][Pro] used as a chiral ligand: Rs = 5.3 for D,L-tryptophan and Rs = 2.2 for D,L-tyrosine.

AB - The densities of aqueous solutions of amino acid ionic liquids (AAILs) based on 1-alkyl-3-methylimidazolium cations and L-prolinate anions [C(n)mim][Pro] (n = 4, 8, 12) in the concentration range 0-97 wt% were measured at several constant temperatures in the range 293.15-318.15 +/- 0.05 K. It has been found that in the range of high AAIL concentrations the dependence of the density values on the AAIL mole fraction for binary water+[C(n)mim] [Pro] solutions is nonlinear. The refractive indices of aqueous solutions of these AAILs in the concentration range 0-97 wt % and the electrical conductivities of aqueous [C(n)mim][Pro] (n = 8, 12) solutions were measured at temperature 298.15K. Critical micelle concentrations (cmc) of AAILs, degree of counterion binding (beta), standard Gibbs energy of micellization (Delta G degrees(m)) for them were estimated from the experimental data. The dependences of the cmc, beta and Delta G degrees(m), on the length of the alkyl chain of the cations were discussed. The synthesized AAILs [C(n)mim] [Pro] were examined as chiral selectors for the separation of D,L-tryptophan and D,L-tyrosine enantiomers using the ligand exchange capillary electrophoresis. The highest resolution factors Rs are observed in the case of [C(4)mim][Pro] used as a chiral ligand: Rs = 5.3 for D,L-tryptophan and Rs = 2.2 for D,L-tyrosine.

KW - Amino acid ionic liquids

KW - Density

KW - Specific electrical conductivity

KW - Thermodynamic characteristics

KW - Capillary electrophoresis

KW - ACID IONIC LIQUIDS

KW - MICELLE FORMATION

KW - LIGAND-EXCHANGE

KW - PHYSICOCHEMICAL PROPERTIES

KW - AGGREGATION BEHAVIOR

KW - AMINO-ACIDS

KW - SURFACTANTS

KW - MIXTURES

UR - http://www.scopus.com/inward/record.url?scp=85042311656&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/densities-refractive-indices-conductivities-aqueous-cnmimpro-solutions-n4-8-12-micellization-capilla

U2 - 10.1016/j.colsurfa.2018.02.014

DO - 10.1016/j.colsurfa.2018.02.014

M3 - статья

VL - 544

SP - 137

EP - 143

JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects

JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects

SN - 0927-7757

ER -