【作者】 刘雷；

【导师】 史向阳；

【作者基本信息】 东华大学 ， 应用化学， 2016， 硕士

【摘要】 金属纳米颗粒由于具有一些优良的物理化学性质从而引起了人们广泛的研究兴趣,但是金属纳米颗粒在水溶液中易团聚和难以重复使用,这就需要一个载体以提高颗粒的稳定性和重复使用性能。在寻找合适载体的过程中,本论文发现普通常见、价格低廉、机械性能好、便于表面修饰的滤纸是一种理想的载体。本文利用聚乙烯亚胺来包裹金、钯、银纳米颗粒,并分别将这三种纳米金属颗粒成功地固载在滤纸上,接着通过SEM、TEM、EDS、TGA、UV-vis和ICP-OES等测试方法对制备出的复合材料进行表征,并且对催化和重复使用性能进行测试。本论文主要包括以下三方面的研究工作:一、制备、表征金纳米颗粒固载滤纸,并研究其催化和重复使用性能。首先以聚乙烯亚胺(PEI)作为稳定剂制备出聚乙烯亚胺包裹的金纳米颗粒(Au PENPs),然后通过PEI和滤纸之间的静电作用将其固载在滤纸上。从TEM图片可以看出固载后的Au PENPs呈现椭圆状,均匀分布在滤纸纤维的表面,且直径为3.5±0.9 nm、固载率为1.4%。实验的结果表明Au PENPs固载滤纸对4-硝基苯酚(4-NP)的还原反应具有良好的催化和重复使用性能。二、制备、表征纳米钯固载滤纸,并研究其催化和重复利用性能。首先通过自组装方法先后将PEI和PdCl42-固载在滤纸上,然后通过载滤纸催化4-NP和六价铬(Cr(VI))的还原反应来评估复合材料的催化和重复使用性能。实验结果显示纳米钯固载滤纸具有良好的催化和重复使用性能。三、制备、表征银纳米颗粒固载滤纸,并研究其催化和重复使用性能。首先以PEI作为稳定剂制备出聚乙烯亚胺包裹的银纳米颗粒(Ag PENPs)。从Ag PENPs的TEM图片,可以看出制备的纳米颗粒为椭圆状、分布均匀、无团聚。经过统计计算,Ag PENPs的直径为4.6±1.3 nm。将滤纸浸泡在制备Ag PENPs溶液中,得到固载率为6.6%的Ag PENPs固载滤纸。研究表明Ag PENPs固载滤纸对4-NP的还原反应具有良好的催化性能,同时Ag PENPs固载后也具有良好的重复使用性能。金属纳米颗粒固载滤纸具有制备工艺简单、成本低、催化和重复使用性能好等优点,同时这种制备复合材料的方法也可以运用到其它纳米金属,因此金属纳米颗粒固载滤纸在催化、传感和生物医学等领域具有很强的应用潜力。更多还原

【Abstract】 Metallic nanoparticles have attracted tremendous interest due to their excellent chemical and physical characteristics, but the application of them in solutions is limited due to their poor stability and recyclability. To overcome such shortcoming, metallic nanoparticles need to be immobilized onto a carrier. In the process of searching for a suitable carrier, we found that the filter paper is a ideal carrier with cost-effectiveness, good mechanical properties and easy modification. Branched polyethyleneimine(PEI) was used as a template to synthesize metallic nanoparticles. PEI-entrapped gold nanoparticles(Au PENPs), PEI-entrapped palladium nanoparticles(Pd PENPs) and PEI-entrapped silver nanoparticles(Ag PENPs) were immobilized onto filter paper, respectively. The formed metallic nanoparticle-containing filter paper was characterized by various techniques such as SEM, TEM, EDS, TGA, UV-vis and ICP-OES, and the catalytic activity and reusability of the composite filter paper were also investigated. This paper includes three parts:First, the preparation, characterization, catalytic activity and reusability of Au PENP-assembled filter paper were studied. At first, the formed Au PENPs using PEI as stabilizers were assembled onto filter paper through electrostatic interaction. The assembly of Au PENPs with a mean diameter of 3.5 ± 0.9 nm onto filter paper was characterized via different techniques. The catalytic activity of the Au PENP-containing filter paper with a loading percentage of 1.4% was evaluated by transformation of 4-nitrophenol(4-NP) to 4-aminophenol(4-AP). We show that the formed Au PENP-assembled filter paper has excellent catalytic activity and reusability.Second, the preparation, characterization, catalytic activity and reusability of Pd PENP-assembled filter paper were investigated. The PEI and PdCl42- were absorbed onto filterSuch development of Au, Pd, Ag PENP-assembled filter paper may be applicable for the immobilization of other metal NPs onto filter paper for various applications in catalysis, sensing, and biomedical sciences.更多还原