Size effect on thermodynamic properties of CaMoO_4 microano materials and reaction systems

摘要

CaMoO_4 microano hollow spheres with three different sizes were prepared via a reverse-microemulsion route at room temperature. Through designing a novel thermochemical cycle, the relationship between thermodynamic properties of nano CaMoO_4 and bulk CaMoO_4 was built. Combined with in situ microcalorimetry, change regularities for the thermodynamic properties of the prepared CaMoO_4 microano materials and reaction systems were obtained. The results reveal that size effect has significant influence on thermodynamic properties of microano materials and reaction systems. Along with the size decreasing, the standard molar enthalpy, standard molar Gibbs free energy and standard molar entropy of reaction of microano reaction systems decreased, but the standard molar enthalpy of formation, standard molar Gibbs free energy of formation and standard molar entropy of microano materials increased.