The Reversible Pressure-driven Assembly Of Goldnanoparticles

In this paper,the assembly process of gold nanoparticles was studied by means of diamond anvil cell and in situ absorption spectroscopy.Changing the thermodynamic parameters of the ligands,the temperature and the pressure of the nanoparticles,and the dependence of the pressure on the assembly of gold nanoparticles by measuring the scattering spectra of gold nanoparticles.The research contents include the following three parts:(1)based on the DLVO theory,a theoretical model of pressure dependence was established by considering the influence of pressure on the concentration,the dielectric constant and the Debye length.The pressure was introduced into the assembly system of gold nanoparticles,and it was proved that the gold nanoparticles could complete the reversible assembly process under pressure.The use of gold nanoparticles on the surface of the electric double layer structure,distribution of ions in solution is calculated by the Poisson-Boltzmann equation,the Gibbs free energy change said to calculate the potential energy of gold nanoparticles between the osmotic pressure,pressure to get gold nanoparticles under variable potential variation curves,the theoretical analysis of gold nanoparticles the thermodynamic behavior of particle solution.(2)compared to two(of ligand sulfonylphenyl)phenyl phosphine(BSPP)absorption spectra of gold nanoparticles in solution and citrate,verified the reversible BSPP ligand can achieve gold nanoparticles temperature driven assembly.The absorption spectra and transmission electron microscopy,the specific analysis of the two ligands and the concentration of salt and sodium chloride on the gold nanoparticle solution thermodynamic stability,to complete the replacement of gold nanoparticles solution ligands,the stability of BSPP in citrate has a better proof.(3)for the first time,the pressure was introduced into the gold nanoparticle gel system to achieve the reversible assembly of gold nanoparticles.Based on the analysis of the effect of pressure on the reversible assembly of gold nanoparticles,the reversibility of gold nanoparticle gel samples was verified by measuring the absorption spectra.There is no comparison of agarose gel samples was found by agarose gel on gold nanoparticles and reversible assembly is not necessary,but it has a very positive effect on the chain and the observation of the absorption spectra of gold nanoparticles to limit.However,due to the limitation of the high pressure experimental technique,we have prepared a sample of gold nanoparticles without agarose gel,and the reversible absorption spectra of the samples in 0 GPa – 1.2 GPa have been completed by pressure regulationIn summary,we will introduce the pressure of gold nanoparticles assembly system,affected by the effects of pressure on the parameters of solution concentration,the dielectric constant and the electron Debye length,building a theoretical model of pressure dependent.Through the study of the effect of different ligands,sodium chloride and temperature on the gold nanoparticle solution,the reversible assembly of gold nanoparticles under pressure control was realized by using BSPP as ligand.This paper systematically studied the in situ high pressure pressure as the effects of thermodynamic parameters on gold nanoparticle self-assembly process of absorption spectrum,deepened to the assembly process of the deep understanding of the physical mechanisms,for the preparation of the peculiar optical properties of micro nano optical devices provide more control means and ideas.