Surface tension of 3-amino-1-propanol and (RS)-2-Amino-1-propanol in aqueous solution were measured in the temperature range from 293.15 to 308.15 K at intervals of 5 K over the whole concentration range. The concentration dependence of surface tension for both amino alcohols aqueous solution shows a similar behavior to that observed for other polar solutes in water. The surface tension data of 3-amino-1-propanol and 2-amino-1-propanol at the selected temperatures were accurately described using the integral Gibbs adsorption equation, the virial equation, and the Langmuir-Gibbs equation of state. The activity coefficients γ for both solutes were determined using the virial equation and found to be unitary within the experimental uncertainty, which was confirmed by the accurate representation of the experimental data by the Langmuir Gibbs Equation of State (LGSEOS). The standard adsorption energy calculated for both solutes from the fitting parameters of LGSEOS to the experimental data indicates that (RS)-2-amino-1-propanol has a higher hydrophobic character and a greater tendency to migrate to the surface than 3-amino-1-propanol as shown by the more negative ΔGads0 values for this solute than for 3-amino-1-propanol.
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