Geranio L, Heuberger M, Nowack B
Technology and Society Laboratory, and Laboratory of Advanced Fibers, Empa - Swiss Federal Laboratories for Materials Testing and Research, CH 9014 St. Gallen, Switzerland.
Environ Sci Technol. 2009 Nov 1;43(21):8113-8. doi: 10.1021/es9018332.
The widespread use of silver nanoparticles (Ag-NPs) in commercial products, especially textiles, will likely result in an unknown spread of Ag into the environment. The quantification and characterization of the Ag released from nano-Ag-products is an important parameter needed to predict the effect of Ag-NPs on the environment. The aim of this study was to determine the amount and the form of Ag released during washing from nine fabrics with different ways of silver incorporation into or onto the fibers. The effect of pH, surfactants, and oxidizing agents was evaluated. The results show that little dissolution of Ag-NPs occurs under conditions relevant to washing (pH 10) with dissolved concentrations 10 times lower than at pH 7. However, bleaching agents such as hydrogen peroxide or peracetic acid (formed by the perborate/TAED system) can greatly accelerate the dissolution of Ag. The amount and form of Ag released from the fabrics as ionic and particulate Ag depended on the type of Ag-incorporation into the textile. The percentage of the total silver emitted during one washing of the textiles varied considerably among products (from less than 1 to 45%). In the washing machine the majority of the Ag (at least 50% but mostly >75%) was released in the size fraction >450 nm, indicating the dominant role of mechanical stress. A conventional silver textile did not show any significant difference in the size distribution of the released silver compared to many of the textiles containing nano-Ag. These results have important implications for the risk assessment of Ag-textiles and also for environmental fate studies of nano-Ag, because they show that under conditions relevant to washing, primarily coarse Ag-containing particles are released.
银纳米颗粒（Ag-NPs）在商业产品尤其是纺织品中的广泛使用，可能会导致银在环境中未知的扩散。从纳米银产品中释放出的银的定量和表征是预测Ag-NPs对环境影响所需的一个重要参数。本研究的目的是确定九种通过不同方式将银掺入纤维或附着于纤维上的织物在洗涤过程中释放的银的量和形态。评估了pH值、表面活性剂和氧化剂的影响。结果表明，在与洗涤相关的条件下（pH值为10），Ag-NPs的溶解很少，溶解浓度比pH值为7时低10倍。然而，过氧化氢或过氧乙酸（由过硼酸盐/TAED体系形成）等漂白剂可大大加速银的溶解。从织物中以离子态和颗粒态银形式释放的银的量和形态取决于银掺入纺织品的类型。在一次洗涤过程中，纺织品释放的总银的百分比在不同产品之间差异很大（从不到1%到45%）。在洗衣机中，大部分银（至少50%，但大多>75%）以大于450纳米的粒径级分释放，这表明机械应力起主要作用。与许多含纳米银的纺织品相比，传统银纺织品释放的银在粒径分布上没有任何显著差异。这些结果对银纺织品的风险评估以及纳米银的环境归宿研究具有重要意义，因为它们表明在与洗涤相关的条件下，主要释放的是粗大的含银颗粒。
