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Size and shape control of metal nanoparticles using dendron ligands

使用树枝状配体控制金属纳米颗粒的尺寸和形状

基本信息

批准号：
18510088
负责人：
TORIGOE Kanjiro
金额：
$ 2.54万
依托单位：
Tokyo University of Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18510088/
关键词：
metal nanoparticles dendron ligand microflow reactor reversed micelle size control マイクロリアクター

项目摘要

Physical and chemical properties of metal nanoparticles strongly depend on their size and shape, thus their control is very important in both basic researches and applications. We have attempted to control the particle size by two different systems : microflow reactor and reversed micelle.First in the microflow reactor system, poly (benzyl ether) dendron ligands of generations 1 to 4 with an amino focal group have been synthesized. These dendron ligands were mixed with an organometallic compound (palladium (II) acetate, Pd(OAc)_2) in an inert solvent with a high boiling point (diphenyl ether, bp.259℃) and pushed out from a syringe to a silica microflow reactor with 150-300μm in inner diameter. The Pd nanoparticles were yielded by thermal decomposition of Pd (OAc)_2. In this system, effects of flow parameters, i.e. reaction temperature, inner diameter of the reactor, flow rate, concentrations ofprecursor and ligand, have been investigated. The following results were obtained : (1) The p … More article size increases from 2.7 to 4.8 nm with increasing the reaction temperature, (2) the particle size decreases with increasing linear flow rate but does not depend on the volume flow rate. Moreover, (3) the particle size shows the minimum at r=1-2where r is defined by the dendrimer to metal precursor molar ratio. We found also that the particle size does not vary in a wide concentration range of the metal precursor (1-27mM) with keeping an excellent monodispersity, while in the batch reactor, a significant increase in both the mean particle size and the polydispersity was observed with increasing the precursor concentration. This implies that the microflow reactor system is feasible for mass production of size-regulated metal nanoparticles.Second, poly (benzyl ether) dendrons attached with a polyethyleneglycol (PEG) chain at the focal point were synthesized for making reverse micelles in organic solvents. Since the hydrophil/lyophil balance (HLB) varies with the length of PEG chain(n), we started with n=6. However, it was not long enough to solubilize water in the reverse micelle. Therefore we synthesized the dendron with a longer PEG chain, n=8 and 11.5. The dendon with the longest PEG chain has been found to solubilize water in the reverse micelles in toluene. However, it is not yet clear that these micelles can work as a reservoir for metal nanoparticles. Less

金属纳米颗粒的物理和化学性质强烈依赖于其尺寸和形状，因此对其的控制在基础研究和应用中都非常重要。我们尝试了两种不同的系统来控制粒径：微流反应器和反胶束系统。首先在微流反应器系统中，合成了第1 ~ 4代带有氨基焦点基团的聚苄基醚树枝状配体。将这些树枝状配体与有机金属化合物（乙酸钯（II），Pd（OAc）_2）在高沸点的惰性溶剂（二苯醚，bp.259℃）中混合，从注射器中推出到内径为150-300μm的二氧化硅微流反应器中。Pd纳米粒子是通过Pd（OAc）_2的热分解得到的。考察了反应温度、反应器内径、流量、前驱体和配体浓度等流动参数对反应的影响。结果表明：（1）在不同的温度下， ...更多信息随着反应温度的升高，颗粒尺寸从2.7 nm增加到4.8 nm;（2）颗粒尺寸随着线性流速的增加而减小，但不依赖于体积流速。此外，（3）颗粒尺寸在r=1- 2时显示出最小值，其中r由树枝状聚合物与金属前体的摩尔比定义。我们还发现，粒径在金属前体的宽浓度范围内（1- 27 mM）不变化，保持优异的单分散性，而在间歇式反应器中，随着前体浓度的增加，观察到平均粒径和多分散性的显著增加。这表明微流反应器系统可用于大规模制备尺寸可控的金属纳米粒子。第二，合成了在焦点处连接有聚乙二醇（PEG）链的聚苄基醚树枝状分子，用于在有机溶剂中制备反胶束。由于亲水/亲液平衡（HLB）随PEG链的长度（n）而变化，我们从n=6开始。然而，它不足以溶解反胶束中的水。因此，我们合成了具有较长PEG链的树枝化基元，n=8和11.5。已发现具有最长PEG链的树枝状结构在甲苯中的反胶束中增溶水。然而，目前尚不清楚这些胶束是否可以作为金属纳米颗粒的储存库。少