Synthesis and Crystal Structures of Gold Nanowires with Gemini Surfactants as Directing Agents

Abstract

The preparation of crystalline gold nanowires (NWs) by using gemini surfactants as directing agents through a three-step seed-mediated method is reported. Unlike the nanorods with relatively low aspect ratios (typically below 20) obtained by using cetyltrimethylammonium bromide as a directing agent, the NWs obtained in this investigation can reach up to 4.4 μm, and the largest aspect ratio is calculated to be 210. For this, each of seven different gemini surfactants are utilized as directing agents, and the length and/or aspect ratio of the NWs can be tuned by varying the hydrocarbon chain lengths of the gemini surfactants. Both single and twinned crystalline structures are elucidated by selected-area electron diffraction and high-resolution transmission electron microscopy studies. The use of gemini surfactants not only advances the synthesis of gold nanostructures, but improves the understanding of the growth mechanism for seed-mediated growth.

Chemical Transformation of Nanorods to Nanowires: Reversible Growth and Dissolution of Anisotropic Gold Nanostructures

“…In addition, gold nanowires (AuNWs) are of great interest due to their excellent thermal and electrical conductivities − which are important in the fabrication of optoelectronic devices − and biological sensors . Several methods such as an ultrahigh vacuum transmission electron microscope (TEM) electron thinning technique and biological, − template-assisted, and chemical − methods have been reported for the synthesis of AuNWs. Nanowires produced by template-assisted methods have large width and very low overall yield, whereas assemblies of nanoparticles produce nanowires of poorly defined morphology.…”

Synthesis and the growth mechanism of ultrafine silver nanowires by using 5-chloro-2-thienylmagnesium bromide as the additive

“…Therefore, the ultrane Ag NWs synthesized in this work should have a penta-twined structure and are bounded by ve {100} side faces and ten {111} end faces. 19,23 SEM images of Ag NWs before and aer purication further display that the original Ag NWs contain some nanoparticles, while cleaned Ag NWs with the length over 15 mm are obtained aer centrifugation treatment (Fig. 3a and b).…”

Self‐Assembly of Anionic Gemini‐Surfactant‐Assisted Fabrication of Copper Oxide Nanostructures

“…Recently, quite a few papers have reported surfactant-assisted fabrication nanostructures. [13][14][15] It is found that GS in aqueous solution provided a soft template effect and directed the orientated growth of nanocrystals under certain condition. According to further research, as a major influencing factor on the shape of nanocrystals, the aggregation morphology of surfactants can be adjusted by molecule self-assembly.…”

“…Zhang, reported that the controllable self‐assembly could be realized by tuning the amphiphilicity of building blocks, and then introduced the self‐assembly strategies driven by noncovalent interactions or dynamic covalent bonds. Recently, quite a few papers have reported surfactant‐assisted fabrication nanostructures . It is found that GS in aqueous solution provided a soft template effect and directed the orientated growth of nanocrystals under certain condition.…”