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.