金纳米颗粒压制组装的可逆调控

发布时间：2018-01-28 22:31

本文关键词： 金纳米颗粒高压可逆组装配体置换吸收光谱琼脂糖　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文利用金刚石对顶砧加压装置和原位吸收光谱研究了在压力下金纳米颗粒凝胶溶液中金纳米颗粒组装过程。改变金纳米颗粒的配体、溶液的温度和压力等热力学参量,通过测量金纳米颗粒的散射光谱表征金纳米颗粒组装对压力的依赖关系。研究内容具体包括了以下三部分:(1)借鉴DLVO理论,通过考虑压力对金纳米颗粒凝胶溶液的浓度、介电常数及电子的德拜长度等参数的具体影响,建立了一个压力依赖的理论模型。将压力引入了金纳米颗粒的组装理论体系中,证明了金纳米颗粒在压力调控下能够完成可逆性组装过程。利用金纳米颗粒的表面双电层结构,通过泊松——玻尔兹曼方程计算溶液中的离子分布,运用吉布斯自由能表示渗透压来计算金纳米颗粒间势能的变化,得到以压力为变量下金纳米颗粒间势能随距离的变化曲线,从而对金纳米颗粒溶液的热力学行为进行理论分析。(2)对比了配体为二(对磺酰苯基)苯基膦(BSPP)和柠檬酸根的金纳米颗粒溶液吸收光谱,验证了BSPP为配体可以实现温度驱动的金纳米颗粒的可逆组装。通过吸收光谱和透射电子显微镜,实验中具体分析了两种配体以及氯化钠的盐浓度对金纳米颗粒溶液热力学稳定性的影响,完成了金纳米颗粒溶液配体的置换,证明了BSPP相较柠檬酸根具有更好的稳定性。(3)首次,将压力引入到金纳米颗粒凝胶体系中,实现了金纳米颗粒的压致可逆组装。通过分析压力对金纳米颗粒的可逆组装的影响,通过测量吸收光谱验证了金纳米颗粒凝胶样品调控的可逆性。对比有无琼脂糖凝胶的样品后发现并证明了琼脂糖凝胶对金纳米颗粒可逆组装并不是必要的,但其对限制金纳米颗粒的成链及对吸收光谱的观察有十分积极的作用。但由于高压实验技术的限制,我们配置了没有琼脂糖凝胶的金纳米颗粒样品,并通过压力调控,完成了在0GPa——1.2GPa之间样品可逆的吸收光谱综上所述,我们将压力引入金纳米颗粒组装体系中,通过考察压力对溶液的浓度、介电常数及电子的德拜长度等参数的影响,建立了一个压力依赖的理论模型。通过研究了不同配体、氯化钠和温度对金纳米颗粒溶液的影响,利用BSPP为配体实现了金纳米颗粒在压力调控下的可逆组装。本工作利用高压原位吸收光谱系统地研究了压力作为热力学参量对金纳米颗粒组装过程的调控效应,加深了对组装过程深层次物理机制的理解,为制备具有奇特光学性质的微纳光学器件提供了更多的调控手段和思路。
[Abstract]:In this paper, the assembly process of gold nanoparticles in gold nanoparticles gel solution under pressure was studied by using diamond anvil pressure apparatus and in situ absorption spectra. The ligand of gold nanoparticles was changed. Thermodynamic parameters such as temperature and pressure of solution. The dependence of pressure on the assembly of gold nanoparticles was characterized by measuring the scattering spectra of gold nanoparticles. The research includes the following three parts: 1) using DLVO theory for reference. The influence of pressure on the concentration, dielectric constant and Debye length of gold nanoparticles was considered. A pressure-dependent theoretical model was established, and the pressure was introduced into the assembly theory system of gold nanoparticles. It is proved that gold nanoparticles can complete the reversible assembly process under the control of pressure. The distribution of ions in the solution is calculated by Poisson Boltzmann equation using the surface double layer structure of gold nanoparticles. The Gibbs free energy is used to represent the osmotic pressure to calculate the change of the potential energy between gold nanoparticles, and the curve of the potential energy between gold nanoparticles with distance under the pressure variable is obtained. The thermodynamic behavior of gold nanoparticles solution was theoretically analyzed. (2) the absorption spectra of gold nanoparticles with bis (p-sulfonylphenyl) phenyl phosphine (BSPP) and citrate were compared. It is proved that BSPP as ligand can realize reversible assembly of gold nanoparticles driven by temperature. Absorption spectra and transmission electron microscopy (TEM) are used. The effect of salt concentration of two ligands and sodium chloride on the thermodynamic stability of gold nanoparticles solution was analyzed in detail, and the ligand replacement of gold nanoparticles solution was completed. It is proved that BSPP has better stability than citrate.) for the first time, the pressure is introduced into the gold nanoparticles gel system. The pressure induced reversible assembly of gold nanoparticles was realized, and the effect of pressure on the reversible assembly of gold nanoparticles was analyzed. The reversibility of gold nanoparticles was verified by measuring the absorption spectra. Comparing the samples with or without agarose gel, it was found and proved that agarose gel was not necessary for the reversible assembly of gold nanoparticles. However, it has a very positive effect on limiting the formation of gold nanoparticles and observation of absorption spectra. However, due to the limitation of high-pressure experimental technology, we have configured gold nanoparticles without agarose gel. The reversible absorption spectra of the samples between 0 GPa--1.2 GPA were achieved by pressure regulation. In summary, the pressure was introduced into the gold nanoparticles assembly system. By investigating the influence of pressure on the concentration of solution, dielectric constant and Debye length of electron, a pressure dependent theoretical model was established. Different ligands were studied. Effects of sodium chloride and temperature on gold nanoparticles solution. The reversible assembly of gold nanoparticles under pressure control was achieved by using BSPP as ligand. In this work, the pressure as a thermodynamic parameter for the assembly process of gold nanoparticles was systematically studied by high pressure in situ absorption spectroscopy. Effects. The deeper understanding of the physical mechanism of the assembly process provides more control means and ideas for the fabrication of micro / nano optical devices with peculiar optical properties.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;O521

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