Investigations into the electrostatically induced aggregation of Au nanoparticles
Investigations into the electrostatically induced aggregation of Au nanoparticles
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DOI：
10.1021/la000316k
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发表时间：
2000-11-14
期刊：
影响因子：
3.9
通讯作者：
Willner, I
中科院分区：
文献类型：
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作者：
Shipway, AN;Lahav, M;Willner, I
溶液中Au纳米粒子的聚集受阳离子和寡聚阳离子物种的诱导和影响。这种溶液状态的聚集与表面上的多层形成有相似之处，但由于纳米颗粒在溶液中的内在不稳定性，这种聚集更容易。聚集之后进行透射电子显微镜（TEM）和在吸收光谱中λ = 600-900 nm处出现特征。结果发现，这些功能是一个功能的因素，如聚集体的大小，电荷，浓度，以及混合的成分的方法，它们可以与聚集形态。似乎有两种机制可以引起聚集。多电荷聚集体可以将纳米颗粒结合在一起形成致密的聚集体，在约100 nm处显示出确定的吸光度。λ = 700 nm，而单电荷聚集体导致较慢的聚集成具有较不确定的吸光度的线状聚集体。而多电荷聚集体可以“交联”表面上的多层结构中的层，单电荷聚集体不能。
The aggregation of Au nanoparticles in solution is induced and influenced by cationic and oligocationic species. This solution-state aggregation bears similarities to multilayer formation on surfaces but is more facile because of the nanoparticles' intrinsic instability in solution. Aggregation is followed by transmission electron microscopy (TEM) and the appearance of features at lambda = 600-900 nm in the absorbance spectrum. It is found that these features are a function of factors such as the aggregant size, charge, and concentration, and the method of mixing the components, and they can be related to aggregate morphology. It seems that there are two mechanisms that can act to cause aggregation. Multiply charged aggregants can bind nanoparticles together into dense aggregates, displaying a defined absorbance at ca. lambda = 700 nm, whereas singly charged aggregants cause a slower aggregation into string-like aggregates with a less defined absorbance. Whereas multiply charged aggregants can "cross-link" the layers in a multilayer structure on a surface, singly charged aggregants cannot.