Instability Analysis For Disperse System

As the important thermodynamics property, phase transitions have widely appled to ind- ustry and agriculture. The instability analysis is the key to the study of phase transitions. for molecular fulids, we find that different fluids exhibit very different types of instability, for instance, there are otropic-to-ferroelectric transition, demixing transition, condensation instab- ilities, and so on. In the study of disperse system, we consider the dispersed phase as'molecular'. The intermolecular potential u ( rω₁ω 2) not only depends on their separation, but also on their orientationsω₁,ω 2. The dependence of the intermolecular forces on the molecul- er orientations leads to qualitatively new features in the liquid properties, when compared to atomic liquids. The instability study for molecular fulids which is based on various shapes is used to realize the microscopic properties deeply, and to a certain extent it is the guide role to the development and application of new materials.In this work, we have employed Density Functional Methods and integral equations in order to study the phase behavior of molecular fulids. The object is the molecular fulids which is based on various shapes. It is convenient to the study, if we expand the angular correlation functions in spherical harmonics. And, the symmetry operations of the individual molecules leave Physical Properties unchanged. So we consider the impact of symmetry operations on the generalized spherical harmonic expansion. We derive the formalism appropriate for expansive variable. In instability analysis, how to calculate the correlation functions plays an important role. Here, we used the iteration of the Picard type, and obtained an accompanying stability analysis and criteria. Finally, We have computed the liquids composed of planar molecules with C 2v symmetry, named SO2 , have finded the own types of phase transitions.