压电驱动式脉动微混合生成金纳米粒子的研究

发布时间：2018-01-03 08:38

本文关键词：压电驱动式脉动微混合生成金纳米粒子的研究　出处：《吉林大学》2012年硕士论文　论文类型：学位论文

【摘要】：压电驱动式脉动微混合作为一种新型流体微混合方式，在国内属于首创研究，其不仅具有重要的学术研究意义，而且在医学、生物、化学等领域具有重要的应用价值。本文提出的压电驱动脉动微混合系统是压电微泵一个新的应用基础研究，通过对压电微泵驱动电压和频率及混合模式的控制，使柠檬酸钠和氯金酸溶液在Y型微混合器中实现紊流混合，提高了化学反应速率及反应质量，从而实现了金纳米粒子的可控合成。通过对单腔体和双腔体串联压电微泵理论输出性能的对比，选择了功能体积比更高的双腔体串联压电微泵作为脉动微混合的驱动源，实现高性能流体脉动输出。基于压电微泵设计理论，采用迭片技术，设计、制作出高性能双腔体串联压电微泵，并对此微泵进行了相关性能实验测试。实验结果表明，双腔体串联泵在50V电压200Hz频率条件下流量达到4.2ml/min，压力达到34kPa。基于脉动微混合需要，设计出一种Y型微混合器。利用微混合理论，对微流体在不同输入条件、不同流道尺寸条件下Y型微混合流道中的混合状态进行了Fluent仿真分析。仿真结果表明，当流道截面尺寸为0.4mm×0.4mm，入口流道夹角为60o，两脉动流体输入的相位差为180o，流量幅值为4ml/min，脉动频率为300Hz时，混合度σ约为0.97；当流道截面尺寸为0.4mm×0.4mm，两入口流道夹角为60o，两脉动流体输入的相位差为180o，脉动频率为200Hz，流量幅值为3ml/min时，混合度σ约为0.96。基于以上仿真结果，设计出适合于压电驱动式脉动微混合的Y型微混合器，采用PDMS材料，利用翻模技术制作出微混合器；对微混合器进行了替代溶液实验，并利用高速摄像机采集到流道中脉动混合图像，验证压电驱动式脉动混合模式能提高混合效率与混合质量。采用压电驱动式微混合器进行了金纳米粒子可控合成的实验研究。通过调节压电泵的驱动电压、频率及信号相位差，合成了不同形貌、不同粒径及不同分散性的金纳米粒子。实验结果表明，，当电压为50V，频率为200Hz，异相混合（脉动混合）时，混合效果较好，所生成金纳米粒子较多，粒径均一，分散性较好；对反应溶液中加PVP与不加PVP生成的金纳米粒子进行了研究，发现不加PVP时，粒子团聚严重，加入PVP后，粒子粒径减小，单分散性显著提高；分析不同反应试剂浓度下生成金纳米粒子的实验结果得出，柠檬酸钠浓度为0.5mM时较浓度为1.5mM和6.0mM时生成金纳米粒子的粒径分布、形貌、单分散性好。
[Abstract]:As a new fluid micro-mixing method, piezoelectric pulsating micro-mixing is the first research in China. It is not only of great academic significance, but also in medicine and biology. Chemistry and other fields have important application value. The piezoelectric pulsating micromixing system proposed in this paper is a new applied foundation research of piezoelectric micropump, through the control of the driving voltage, frequency and mixing mode of piezoelectric micropump. The turbulent mixing of sodium citrate and chloruronic acid solution in Y type micromixer improves the reaction rate and reaction quality, thus realizing the controllable synthesis of gold nanoparticles. By comparing the theoretical output performance of single cavity and double cavity series piezoelectric micropump, the double cavity series piezoelectric micropump with higher function volume ratio is selected as the driving source of pulsating micro mixing. Based on the design theory of piezoelectric micropump, the high performance double-cavity series piezoelectric micropump is designed and fabricated by lamination technology. The experimental results show that the flow rate of the double-chamber series pump reaches 4.2 ml / min at the frequency of 50V and 200Hz. The pressure reached 34kPa. Based on the need of pulsating micro-mixing, a Y-type micromixer is designed. The mixing state of Y-shaped micro-mixing channel is simulated by Fluent under different channel sizes. The simulation results show that the section size of the channel is 0.4mm 脳 0.4mm. When the inlet channel angle is 60o, the phase difference of the two pulsating fluids is 180o, the flow amplitude is 4ml / min and the pulse frequency is 300Hz, the mixing degree 蟽 is about 0.97; When the cross section of the channel is 0.4mm 脳 0.4mm, the angle between the two inlet channels is 60o. the phase difference of the two pulsating fluid input is 180o. the pulsation frequency is 200Hz. When the flow amplitude is 3 ml / min, the mixing degree 蟽 is about 0.96. Based on the above simulation results, a Y-type micro-mixer suitable for piezoelectric driven pulsating micro-mixing is designed, using PDMS material. The micro mixer is made by turning mould technology. The experiment of substituting solution for the micro mixer was carried out, and the pulsating mixing images in the flow channel were collected by high speed camera. It was proved that the piezoelectric driven pulsating mixing mode could improve the mixing efficiency and mixing quality. The controlled synthesis of gold nanoparticles was studied using piezoelectric driven micro mixer. Different morphologies were synthesized by adjusting the driving voltage, frequency and signal phase difference of piezoelectric pump. The experimental results show that when the voltage is 50V and the frequency is 200Hz, the mixed effect is better when the particle size is different and the dispersion is different. The gold nanoparticles are more uniform in particle size and have good dispersibility. The gold nanoparticles produced by adding PVP and no PVP in the reaction solution were studied. It was found that the agglomeration of gold nanoparticles was serious without adding PVP, and the particle size decreased and the monodispersity increased significantly after adding PVP. The experimental results of gold nanoparticles at different reaction reagent concentrations showed that the particle size distribution of gold nanoparticles was obtained when the concentration of sodium citrate was 0.5 mm compared with 1.5 mm and 6.0 mm of sodium citrate. Morphology, monodispersity is good.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH38

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