Study of the vaporization process of the rubidium deoxycholate crystal and fibre

The vaporization behaviour of rubidium deoxycholate (RbDC) is investigated. In the first stage, the evaporation of crystallization water occurs and an average enthalpy change ? H0325 = 34±4 kJ mol-1 is derived by a second-law treatment of the vapour data. In the fibre the vaporization of the residue crystallization water presents slower kinetics than in the crystal. In the RbDC, as in the sodium salt, no vaporization is observed until its melting point. Above this temperature (594-596 K) the vapour, constituted by various decomposition products, shows almost reproducible values.