Preparation of hydrophobic nanometer gold particles and their optical absorption in chloroform
Preparation of hydrophobic nanometer gold particles and their optical absorption in chloroform
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DOI：
10.1021/la960150g
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发表时间：
1997-05-28
期刊：
影响因子：
3.9
通讯作者：
Jiang, L
中科院分区：
文献类型：
--
作者：
Fan, CY;Jiang, L
分散在水溶液中的胶体金的制备已被广泛研究。1-5但在有机溶剂中制备胶体金的报道较少。在有机溶剂中制备胶体金与在水溶液中制备胶体金有很大不同。由于静电稳定在有机介质的相对低极性中通常不那么有效，并且有机溶剂的粘度通常低于水的粘度，因此有机相中的胶体颗粒之间存在更频繁的相遇，导致比在水中更快的聚集。已经报道了几种制备金属有机溶胶的方法，例如溶剂萃取/还原技术，6，7气体蒸发技术，8在甲醇或乙醇中在聚合物稳定剂的存在下制备无机颗粒，9，10溶解在乙二醇中的有机金属前体的还原，11和相转移方法。12，13上面提到的一些方法，如“相转移法”和“在甲醇和乙醇中还原”，已经在我们的实验室中用于生产疏水性金颗粒。然而，通过这两种方法制备的颗粒不适合于Langmuir-Blodgett膜形成，因为它们具有亲水性表面。本文提出了一种在氯仿中制备稳定疏水纳米金颗粒的新方法。在高浓度的表面活性剂十六烷基三甲基溴化铵（CTAB）的作用下，金粒子在氯仿中的大小均匀，并且在很长一段时间内保持胶体稳定。随着粒径的减小，其光吸收峰向蓝移。
The preparation of colloidal gold dispersed in an aqueous solution has been extensively studied. 1-5 However there have been only a few reports on the preparation of colloidal gold in organic solvent. The preparation of colloidal gold in organic solvent is quite different from that in aqueous solution. Since electrostatic stabilization is generally not as effective in the relative low polarity of the organic medium and the viscosity of the organic solvent is often lower than that of water, there are more frequent encounters between the colloid particles in the organic phase, leading to a more rapid aggregation than in water. In addition, the low solubility of the metal salts in organic solvent makes reduction of the metal ion to free metal unfeasible.Several methods have been reported for the production of metal organosols, such as the solvent extraction/reduction technique, 6, 7 the gas evaporation technique, 8 inorganic particle preparation in methanol or ethanol with the presence of polymeric stabilizer, 9, 10 reduction of an organometallic precursor dissolved in ethylene glycol, 11 and phase transfer methods. 12, 13 Some of the methods mentioned above, such as the “phase transfer method” and “reduction in methanol and ethanol”, have been used to produce hydrophobic gold particles in our laboratory. However, particles made by these two methods were unsuitable for Langmuir-Blodgett film formation, since they have hydrophilic surfaces. In this report, a new method is presented to produce stable hydrophobic nanometer gold particles in chloroform. With a high concentration of the surfactant CTAB, the gold particles in chloroform were made uniform in size and remain colloidally stable for long periods of time. Their optical absorption peak shifted to blue with a decrease of particle size.