Adsorption of monoterpene alcohols at the water-air interface

The measurements of the surface tension of aqueous solutions of 10 monoterpene alcohols, MAs: (-)--citronellol, geraniol, tetrahydrolinalool, linalool, (-)-menthol, (-)-terpinen-4-ol, p-cymene-8-ol, -terpineol, isoborneol and (-)-borneol were made at T=293K. On the basis of the obtained results the values of the adsorption constant, the excluded area per molecule at the interface and the interaction parameter were determined by fitting the experimental data to various adsorption models. Next the adsorption free energy of studied MAs was determined and discussed in terms of the preferred orientation of studied MAs at the water-air interface and molecular structure of MAs.