Studies of interparticle interactions among some l-α-amino acids and 1,2 (1,3)-propanediols in aqueous solution at 298.15 K

Mixing enthalpies of aqueous glycine, l-α-alanine, l-α-valine, l-α-serine. l-α-threonine and l-α-proline solutions and aqueous 1,2-propanediol and 1,3-propanediol solutions and their dilution enthalpies have been measured with a Thermometric-2277 Thermal Activity Monitor at 298.15 K. Experimental data were treated according to the McMillan-Mayer theory and the heterogeneous enthalpic pairwise interaction coefficients (hxy) of the natural amino acids and propanediol molecules in aqueous solution were obtained. Combining the hxy coefficients of amino acids with glycol and glycerol in aqueous solution reported by our previous works, the effects of number and position of OH groups in polyalcohols on the interactions between them and amino acids are discussed in the terms of solute-solute interactions.