Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States.
Environ Sci Technol. 2012 Jul 3;46(13):7001-10. doi: 10.1021/es203851d. Epub 2012 Feb 15.
Copper nanomaterials are being used in a large number of commercial products because these materials exhibit unique optical, magnetic, and electronic properties. Metallic copper nanoparticles, which often have a thin surface oxide layer, can age in the ambient environment and become even more oxidized over time. These aged nanoparticles will then have different properties compared to the original nanoparticles. In this study, we have characterized three different types of copper-based nanoparticle (NP) samples designated as Cu(new) NPs, Cu(aged) NPs, and CuO NPs that differ in the level of oxidation. The solution phase behavior of these three copper-based nanoparticle samples is investigated as a function of pH and in the presence and absence of two common, complexing organic acids, citric and oxalic acid. The behavior of these three copper-based NP types shows interesting differences. In particular, Cu(aged) NPs exhibit unique chemistry including oxide phases that form and surface adsorption properties. Overall, the current study provides some insights into the impacts of nanoparticle aging and how the physicochemical characteristics and reactivity of nanomaterials can change upon aging.
铜纳米材料由于具有独特的光学、磁学和电子特性，被广泛应用于大量商业产品中。金属铜纳米颗粒通常具有薄的表面氧化层，在环境中会老化，并且随着时间的推移会变得更加氧化。与原始纳米颗粒相比，这些老化的纳米颗粒将具有不同的性质。在这项研究中，我们对三种不同类型的铜基纳米颗粒（NP）样品进行了表征，这些样品分别被指定为 Cu(new) NPs、Cu(aged) NPs 和 CuO NPs，它们在氧化程度上有所不同。研究了这三种铜基纳米颗粒样品在不同 pH 值下以及在两种常见的络合有机酸柠檬酸和草酸存在和不存在的情况下的溶液相行为。这三种铜基 NP 类型的行为表现出有趣的差异。特别是，Cu(aged) NPs 表现出独特的化学性质，包括形成的氧化物相和表面吸附特性。总的来说，本研究提供了一些关于纳米颗粒老化的影响的见解，以及纳米材料的物理化学特性和反应性如何在老化过程中发生变化。
