Ultrasound-mediated synthesis of high-molecular weight polystyrene-grafted silver nanoparticles by facile ligand exchange reactions in suspension.
Ultrasound-mediated synthesis of high-molecular weight polystyrene-grafted silver nanoparticles by facile ligand exchange reactions in suspension.
复制标题
DOI：
10.1002/smll.201300594
复制
发表时间：
2014-01
期刊：
影响因子：
13.3
通讯作者：
H. Pletsch;Ling Peng;Fabian Mitschang;A. Schaper;M. Hellwig;David Nette;A. Seubert;A. Greiner;S. Agarwal
中科院分区：
文献类型：
--
作者：
H. Pletsch;Ling Peng;Fabian Mitschang;A. Schaper;M. Hellwig;David Nette;A. Seubert;A. Greiner;S. Agarwal
报道了超声介导的悬浮液中配体交换法制备聚苯乙烯接枝银纳米粒子。令人惊讶的是，这种方法允许甚至接枝非常高的分子量聚苯乙烯（高达217 - 200克摩尔（-1））具有一个单一的末端硫醇基团在链端。详细研究了配体分子量的作用和配体交换反应的机理。关键因素被确定为通过超声处理和低银含量的液滴形成，这显著提高了末端硫醇端基的可用性。配体交换方法特别是关于高分子量的非凡的相容性归因于在液-液界面处的末端硫醇基团的亲水性取向。通过使用原位方法作为参考方法，其中由于聚合物线圈内没有优选的端基取向，在相当低的分子量下发生团聚，最终证明了这一点。在均相中，只有链长是影响银纳米粒子稳定性的关键因素。
Ultrasound mediated facile ligand exchange method in suspension for the formation of polystyrene-grafted silver nanoparticles is reported. Amazingly, this method allows even grafting of very high molecular weight polystyrenes (up to 217 200 g mol(-1) ) having a single terminal thiol group at the chain end. Detailed studies are carried out to gain insights in the role of molecular weight of the ligands and the mechanism of the ligand exchange reactions. Key factors are determined to be the droplet formation by ultrasonification and low silver content, which enhances the availability of the terminal thiol end group significantly. The extraordinary compatibility of the ligand exchange method in particular regarding high molecular weights is attributed to hydrophilic orientation of the terminal thiol groups at the liquid-liquid interphase. This is proved conclusively by using an in situ method as a reference approach in which agglomeration occurs at considerably lower molecular weights due to the absence of preferred end group orientation within the polymer coil. In homogeneous phase only the chain length is found to be the crucial factor in stabilization of silver nanoparticles.