Silver-poly (dimethylsiloxane) nanocomposite films are prepared by an in-situ synthesis by incubating the polymer film in a silver nitrate aqueous solution and using the reducing properties of the polymer’s curing agent. Silver nanoparticles concentrated in the surface layer of the silver-poly (dimethylsiloxane) nanocomposite are further replaced by gold through a galvanic replacement reaction at the poly (dimethylsiloxane)/gold salt solution interface. It is demonstrated that, as a result of the galvanic replacement, the quasi-spherical silver nanoparticles uniformly distributed on the surface of the polymer are transformed into ribbon-like elongated gold aggregates. The formation of core-shell Ag-Au nanoparticles as an intermediate state of the low-temperature galvanic replacement is evidenced through microscopic and spectral methods. The collapse of this structure, in a later stage of the replacement, leads to the formation of elongated gold aggregates. The mechanism of the galvanic replacement under different conditions is investigated by closely following the evolution of the morphology, composition, and optical properties of the metal nanoparticles.

中文翻译：

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通过聚合物介导的银/金电置换反应合成金-聚（二甲基硅氧烷）纳米复合材料

银-聚（二甲基硅氧烷）纳米复合薄膜是通过原位合成制备的，通过在硝酸银水溶液中孵育聚合物薄膜并利用聚合物固化剂的还原特性。浓缩在银-聚（二甲基硅氧烷）纳米复合材料表面层的银纳米颗粒通过聚（二甲基硅氧烷）/金盐溶液界面处的电置换反应进一步被金置换。结果表明，由于电置换，均匀分布在聚合物表面的准球形银纳米粒子转变为带状细长金聚集体。通过微观和光谱方法证明了核壳银金纳米粒子的形成作为低温电置换的中间状态。在更替的后期，这种结构的坍塌导致细长的金聚集体的形成。通过密切关注金属纳米粒子的形态、组成和光学性质的演变，研究了不同条件下的电置换机制。