Viscosity B-coefficients at 15 and 25 °C for glycine, β-alanine, 4-amino-n-butyric acid, and 6-amino-n-hexanoic acid in aqueous solution

Abstract

Viscosity and density measurements have been made on aqueous solutions of glycine, β-alanine, 4-amino-n-butyric acid, and 6-amino-n-hexanoic acid at 15 and 25 °C. The viscosity B-coefficients B_η and the apparent molal volumes ϕ_v° calculated from the experimental results are related at 15 °C by the equation B_η= 6·53 ϕ_v°–0·151, and at 25 °C by B_η= 5·55 ϕ_v°–0·096. It is suggested that the B-coefficients show that glycine, and to a lesser extent β-alanine, are solvent structure breakers, and that 4-amino-n-butyric acid and 6-amino-n-hexanoic acid are solvent structure makers.