Volumetric properties of amino acids in aqueous solution of nonionic surfactant

The volumetric properties of amino acids (dl-glycine, dl-alanine, dl-serine, l-aspartic acid, l-lysine, and l-leucine) in aqueous solution of nonionic surfactant hexadecyl poly[oxyethylene(25)] alcohol (C16A25) are studied. The values of apparent molar volumes Vϕ, partial molar volumes V2,m0 and volumes of transfer Δt2V2,m0 are calculated. The changes of volumes of transfer are discussed in terms of hydrophilic–hydrophobic interactions. The linear correlation of V2,m0 for a amino acids is utilized to calculate the contribution of the charge groups (NH3+,COO−), CH2 group and other alkyl chains of amino acids to V2,m0.