聚丙烯胺稳定铜纳米粒子的制备及其SERS活性研究

报道了聚丙烯胺稳定的球形和棒状铜纳米粒子的制备方法。在水溶液中空气条件下,通过水合肼还原二价铜离子到铜纳米粒子。聚丙烯胺的作用除稳定粒子防止聚集外,也可使粒子分散在水溶液中。该法的优点是在室温下,无需惰性气体保护,即可制备水溶液中分散的铜纳米粒子。紫外光谱和透射电镜监测了铜纳米粒子的生长过程。发现氢氧化钠的用量,聚丙烯胺浓度,反应时间等因素都影响到铜纳米粒子的组成,尺寸,形貌和聚集程度。氢氧化钠用量决定了制备粒子的组成成分是铜或氧化亚铜。所制备的球形铜纳米粒子表现出优良的表面增强拉曼散射活性。

Poly (allylamine)-stabilized colloidal copper nanoparticles: synthesis and their SERS activities

Poly(allylamine)-stabilized spherical and rod-shaped copper nanoparticles were synthesized by a simple chemical reaction. The synthesis was performed by the reduction of copper (II) salt with hydrazine in aqueous solution under atmospheric air in the presence of poly(allylamine) (PAAm) capping agent. Besides providing long-term stability to the nanoparticles by preventing particle agglomeration, polymer capping agents such as PAAm make the particles dispersible in aqueous solution. Noteworthy advantages of the synthetic method include its production of water dispersible nanoparticles at room temperature without inert atmosphere, making the synthesis more environmentally friendly. The resulting copper nanoparticles were investigated by UV-Vis spectroscopy and transmission electron microscopy. The authors found that several factors, including the amount of NaOH solution, concentration of PAAm, and reaction time, affect the composition, size, morphology, and degree of agglomeration of the resulting copper nanoparticles. The amount of NaOH in the reaction is crucial for the synthesis to result in either pure copper or copper oxide-containing copper nanoparticles as well as to produce the highest possible yield of copper nanoparticles. In addition, the reaction time and concentration of PAAm play key roles in controlling the size and shape of the nanoparticles, respectively. The resulting colloidal copper nanoparticles exhibit large surface-enhanced Raman spectroscopy (SERS) signals.