双金属金银微纳结构激光加工的研究

发布时间：2018-01-25 16:48

本文关键词： 双金属金银微纳结构金银合金激光加工图案化微流控芯片　出处：《吉林大学》2015年硕士论文　论文类型：学位论文

【摘要】：复合金属纳米材料有很优异的光学、电学性能，基于复合金属纳米材料的研究对于物理、化学领域的应用具有极其重要的研究意义。相对于单金属，双金属纳米材料的SERS效应、催化性能以及表面等离子体共振等性能都有优异的表现，双金属金银纳米材料近年来也受到了人们越来越多的的关注。单金属的银纳米材料很不稳定，使其在诸多领域的应用都有局限性。单金属的金虽然稳定，但其在生物、增强拉曼散射等领域的应用没有银的效果好。所以金银复合纳米材料的研究是很有意义的。溶液中加入像硼氢化钠类的还原剂，会使溶液由于有残留过多的BH4-离子而导致硼化物污染而影响双金属金银微纳结构在诸多领域的使用。并且，这对于纳米粒子的后续清洗也是很大的难题。基于以上几点，激光辐照由于其不需要添加额外的还原剂而成为一种可替代的方法。相对于传统的利用γ-ray和X-ray辐照，前者有辐射，后者可行性差，飞秒激光由于其简单安全以及绿色环保的特性成为了一种理想的光还原方法。金属离子的还原是通过在激光辐照下有机溶剂的原位电离和激发所产生的丰富的高能电子和氢自由基实现的。通过Visual Basic程序控制飞秒激光的光点，可实现可设计性的任意图形的微纳结构的组装。由于双金属金银微纳结构中金银比例的不同会影响其在物理化学方面的性质，研究了不同配比的离子前驱体溶液对双金属微纳结构中金银比值的影响。通过调节离子前驱体溶液的配比，达到控制沉积在衬底上的微纳结构中金与银比例的目的。该双金属微纳结构保留了金属材料的性质，比较稳定，置于空气中不易变质，且具有很好的连续性和完整性。近几年由于微纳器件的快速发展，系统要求的金属微纳结构并不是孤立存在的，双金属材料和功能化器件的柔性集成成为了焦点。本研究中利用飞秒激光加工的优势，在激光光动力作用下溶液中发生光还原反应，金银微纳结构以纳米团簇或粒子的形式在微流控通道内沉降于衬底上形成预设的双金属金银微纳结构。实验研究了金银微纳结构在双金属合金催化、微流控芯片、自驱动微机械等领域的应用，并对其可行性进行了初步的分析。将这种双金属金银微纳结构用于催化，能在短时间内快速产生大量的气泡，奠定了其在自驱动微机械等领域的应用基础。基于相转移方法制备的前驱体溶液不止局限于金和银离子，多种金属离子都可以得到应用于飞秒激光加工中的有机相的金属离子前驱体溶液，，例如铁（Fe）铂（Pt）等等。因此这种用飞秒激光光动力还原制备金银微纳结构的方法可扩展适用至多种双金属纳米复合材料的制备。
[Abstract]:Composite metal nanomaterials have excellent optical and electrical properties. The research based on composite metal nanomaterials is of great significance for the application of physical and chemical fields. The SERS effect, catalytic performance and surface plasmon resonance (SPR) of bimetallic nanomaterials are excellent. Bimetallic gold and silver nanomaterials have attracted more and more attention in recent years. Single metal silver nanomaterials are unstable, which makes their applications in many fields limited. But its application in biology, enhanced Raman scattering and other fields is not as good as silver, so the study of gold and silver composite nanomaterials is of great significance. The addition of reducing agents such as sodium borohydride in the solution will result in the contamination of boride due to the excessive residual BH4- ions, which will affect the use of bimetallic gold and silver microstructures in many fields. This is also a big problem for the subsequent cleaning of nanoparticles. Laser irradiation has become an alternative method because it does not need additional reducing agent. Compared with conventional 纬 -ray and X-ray irradiation, the former has radiation, the latter is not feasible. Femtosecond laser is an ideal method for photoreduction because of its simple safety and environmental protection. The reduction of metal ions is caused by in situ ionization and excitation of organic solvents under laser irradiation. Energy electrons and hydrogen radicals. The spot of femtosecond laser is controlled by Visual Basic program. It is possible to achieve the design of arbitrary graphics of micro-nano structure assembly. Due to the difference in the proportion of gold and silver in bimetal gold and silver microstructures will affect its physical and chemical properties. The effect of ionic precursor solution with different ratios on the ratio of gold and silver in bimetallic microstructures was studied. This bimetallic structure retains the properties of the metal material and is stable, and is not easy to deteriorate in the air for controlling the ratio of gold to silver in the micro-nano structure deposited on the substrate. And has very good continuity and integrity. Due to the rapid development of micro / nano devices in recent years, the metal micro / nano structures required by the system do not exist in isolation. The flexible integration of bimetallic materials and functional devices has become the focus. In this study, the advantage of femtosecond laser processing, photoreduction reaction occurred in solution under laser photodynamic action. The as-designed bimetallic gold-silver microstructures were formed on the substrate in the form of nanoclusters or particles. The catalysis of gold and silver microstructures on bimetallic alloys was investigated experimentally. The applications of microfluidic chips and self-driving micromachineries are analyzed preliminarily. The bimetallic gold and silver microstructures can produce a large number of bubbles in a short time. It has laid the foundation of its application in the field of self-driven micro-machinery. The precursor solution based on phase transfer method is not only limited to gold and silver ions, many metal ions can be used in femtosecond laser processing of organic phase metal ion precursor solution. Therefore, this method of photoreduction of gold and silver microstructures by femtosecond laser can be extended to the preparation of many kinds of bimetallic nanocomposites.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TN249

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