Osmotic coefficients and activity coefficients in binary water/5-(hydroxymethyl)furfural and in ternary water/5-(hydroxymethyl)furfural/salt solutions at 298.15 K

Abstract This contribution is about the investigation of osmotic coefficients and the water activity of binary water/ 5-(hydroxymethyl)furfural (5-(hydroxymethyl)furan-2-carbaldehyde, HMF) and ternary water/5-(hydroxymethyl)furfural/salt (salt = NaCl or LiCl) solutions. Osmotic coefficients were determined by vapour pressure osmometry at 298.15 K and 975 hPa. HMF molalities ranged from (0.5 to 5) mol∙kg-1 in the binary solutions, while for the ternary solutions HMF molalities ranged from (1 to 5) mol∙kg-1 with salt molalities equal to (1 or 3) mol∙kg-1. The osmotic coefficients of the binary solutions were approximated with a Pitzer-type function to calculate activity coefficients of HMF in water. Osmotic coefficients of ternary systems were approximated according to the Zdanovskii-Stokes-Robinson (ZSR) semi-ideal mixing rule. Two-parameter fitting (third order terms in the power series) was applied to calculate solute activity coefficients in the ternary solutions.