【摘要】 研究了纳米铜在三聚氰胺吸附过程中的稳定性。通过比较两种不同粒径的纳米铜溶胶与三聚氰胺混合溶液的吸收光谱,发现更小粒径的铜纳米团簇的吸收峰值快速下降并至峰位消失,而粒径稍大的铜纳米粒子的吸收峰值下降较慢;在三聚氰胺吸附过程中,两种粒径的纳米铜溶胶的吸收峰位均未发生红移现象,表明纳米铜没有产生团聚。分析认为三聚氰胺在纳米铜表面的吸附部分取代了纳米铜表面原有的还原剂,使铜单质转化为铜离子,溶液中的纳米铜数量减少,发生纳米铜消溶现象,荧光发射减弱。更小粒径的铜纳米团簇具有更大的有效吸附面积,消溶现象显著,稳定性较低。更多还原

【Abstract】 The stability of nano-sized copper in the process of melamine adsorption was studied.Comparing the absorption spectra of nano-sized copper and melamine solutions with two different sizes,it is found that the absorbance values of copper nanoclusters（CuNCs）with smaller sizes decrease rapidly,and even disappear,while the absorbance values of copper nanoparticles（CuNPs）with bigger sizes decline indistinctively.Meanwhile,no red shift is observed in the spectra.The experimental results indicate that no aggregation of nano-sized copper generates in the adsorption process of melamine,but dissolution occurs.The nano-sized copper is unstable in the mixture solution,especially for the CuNCs with smaller size.By the means of the fluorescence spectra,it is suggested that melamine could replace the reducing agent adhering to the surface of nano-sized copper particles and to promote the conversion of Cu0 to Cu²⁺,and consequently to reduce the content of copper nanoparticles in the solution as well as to weaken its fluorescence emission.更多还原