ABSTRACT
Surface properties of binary mixtures of (alkanol with acetonitrile) have been measured by surface tension method at T=298.15 K and atmospheric pressure. The UNIFAC method is used for calculation activity coefficients of surface and bulk phases. Also, the surface tension has been predicted based on the Suarez method. This method combines a model for the description of surface tension of liquid mixtures with a UNIFAC group contribution method for the calculation of activity coefficient. Two techniques for calculation of molar surface areas, based on Paquette areas and Rasmussen areas are tested. On comparing the computed values of surface tension by the present approaches with experimental data, satisfactory results have been observed. In addition, the relative Gibbs adsorption and the surface mole fraction have been evaluated using this model. It is possible to calculate the thickness of liquid-vapor interfaces starting from surface tension data. A novel procedure is developed to obtain the thickness of liquid-vapor interfaces as a function of composition in binary systems.
ABSTRACT
A novel polyoxometalate-cation exchanger, titanium(IV) molybdophosphate (TMP) has been synthesized under varying conditions. The material was characterized by X-ray diffraction, infrared spectroscopy, inductively coupled plasma and thermogravimetry techniques. Its stability was investigated in water, dilute acids, alkaline solutions, and high temperature up to 750 degrees C. Ion-exchange capacity and distribution coefficients (K(d)) for twenty-nine radionuclides and metal ions have been determined. It was found that the TMP has high affinity for Cs(+), Sr(2+), UO(2)(2+), Ba(2+), Pb(2+), Tl(+), Zn(2+), Rb(2+) and Zr(4+) ions. The results of binary separation of metal ions showed that TMP can be potentially useful for analytical applications.
