Kirkwood-buff Theory For Hydrogen Bonding Fluids And Its Application

Hydrogen bonding(HB)fluids has special structure and wide range of applications in scientific research,it's plays an important role in chemistry,biomedical,physics and other fields.Kirkwood-Buff(KB)theory is great of importance to the investigation of the local structure and properties.In this dissertation,it's focused on investigate the KB integral of HB fluids,as well as study the aggregate structure,phase balance,and the relevant thermodynamic quantities of HB fluids.Firstly,on the basis of the principle of statistical mechanics,the grand potential functional of HB interaction is constructed by the density functional theory(DFT).Furthermore,the equilibrium density profiles and the radial distribution function(RDF)are obtained.At the same time,the KB integral of fluids calculated at different bulk density,functionality and strength of hydrogen bonding.It's expected that results are helpful to study the thermodynamic properties and the phase structures of fluids.The dissertation is divided into four parts,the main contents are as follows:Chapter 1: Introduction.This chapter mainly gives an introduction to the research background,research methods and its significance,which includes the characteristics of fluids,the KB integrals development and its applications.Furthermore,a brief history of the development about density functional theory and its research status were also reviewed.At last,explanation the main research about this paper.Chapter 2: Kirkwood-Buff integral for HB fluids.This article briefly describes the development of HB fluids and its relative models.The grand potential functional is constructed by using DFT incorporated with the fundamental measure theory(FMT)and modified fundamental measure theory(MFMT).Then,the functional of the free energy can be expressed.Moreover,the equilibrium density distribution function and the radial distribution function can be obtained by minimizing the grand potential functional,under this the KB integral is calculated to find the effects of bulk density and HB interaction.It's found that both the bulk density and HB interaction have influence for KB integral and integral value.Chapter 3: Phase balance of HB fluids.As an application of the KB theory of HB fluids.based on the principle of fluids phase balance,the phase diagram of the HB fluids associated with T* ~ ?* is given.Moreover,according to the characteristics of the phase diagram,the effects of fluid molecular interactions on the phase equilibrium properties were also addressed.Finally,In the condition of phase balance,the KB integral is calculated to find the effects of functionality and approximate temperature in different states.Meanwhile,fluid phase behavior and aggregation can be significantly regulated by these factors.Chapter 4: Summary.Some conclusions of the investigation of KB theory for HB fluids are summarized.It is expected that the application of KB theory could be paid more attention in the fields of physics and chemistry.