Growth of giant silver dendrites on layer-by-layer assembled films
Growth of giant silver dendrites on layer-by-layer assembled films
复制标题
DOI：
10.1016/j.polymer.2015.03.009
复制
发表时间：
2015-04
期刊：
影响因子：
4.6
通讯作者：
Jia Song;Junxia Hou;Lili Tian;Ying Guan;Yongjun Zhang;X. X. Zhu-X.
中科院分区：
文献类型：
--
作者：
Jia Song;Junxia Hou;Lili Tian;Ying Guan;Yongjun Zhang;X. X. Zhu-X.
银枝晶先前合成，有限的成功，通过化学还原Ag+离子与可溶性还原剂在均匀的溶液。首先将Ag+离子负载到由聚乙烯吡咯烷酮（PVPON）和聚丙烯酸（PAA）制成的氢键层层（LBL）膜中，然后用对苯二酚（HQ）作为还原剂进行化学还原，得到Ag树枝状结构。用SEM、TEM、XRD和光学显微镜对枝晶进行了表征。与在均相溶液中合成的银枝晶相比，这里得到的枝晶要大得多。发育完全的颗粒可达600 μm以上。比在均相溶液中合成的那些大2个数量级（μ 1-5 μm）。此外，这里获得的枝晶是二维的，其沿着LBL膜的表面沿着生长，而不是在均匀溶液中获得的三维枝晶。一个可能的3步生长机制，其中包括快速还原的Ag+离子在膜表面上的Ag种子颗粒的形成，和分形树枝状结构的形成所描述的扩散限制聚集（DLA）模型，提出。
Ag dendrites were previously synthesized, with limited success, via the chemical reduction of Ag+ions with a soluble reducing agent in homogeneous solutions. Here Ag+ions were first loaded in hydrogen-bonded layer-by-layer (LBL) films fabricated from poly(vinyl pyrrolidone) (PVPON) and poly(acrylic acid) (PAA), then reduced chemically using p-hydroquinone (HQ) as a reducing agent to afford Ag dendritic structures. The dendrites were characterized by SEM, TEM, XRD and optical microscope. Compared with the Ag dendrites synthesized in homogenous solutions, the dendrites obtained here are much larger. The fully developed ones can reach a size over 600 μm, ca. 2 orders of magnitude larger than those synthesized in homogenous solutions (∼1–5 μm). In addition, the dendrites obtained here are 2 dimensional which grow along the surface of the LBL film, instead of 3 dimensional as those obtained in homogenous solutions. A possible 3-step growth mechanism, which involves the rapid reduction of the Ag+ions in the film, formation of Ag seed particles on the film surface, and fractal dendritic structure formation as described by the diffusion-limited aggregation (DLA) model, was proposed.