Controlling the size of silver nanowires produced by a tetrabutylammonium dichlorobromide salt-based polyol process: Kinetics of silver crystal growth

摘要

Long silver nanowires (Ag NWs) with lengths of ～65 μm and aspect ratios as high as 1500 were synthesized using a tetrabutylammonium dichlorobromide (TBADCB) salt-based polyol process. The kinetics of crystal growth was studied using stepwise scanning electron microscopy, X-ray diffraction, and surface Plasmon resonance spectroscopy. The diameters of the Ag NWs were shown to be strongly dependent on the molar concentration of TBADCB/AgNO₃. We further demonstrated that the length of the Ag NWs could be controlled by adjusting the reaction temperature at the nucleation step or by varying the stirring speed. NWs with lengths of up to 60 μm and diameters as large as 32 nm were obtained when unidirectional axial stirring was performed at 1000 rpm using a T-shaped impeller, and at an initial nucleation temperature of 20°C. The obtained two-dimensional conducive Ag NW network films exhibited good optical properties, with a low haze of ≤1.0% and 98% transmittance at 60 Ω/sq, similar to the properties of the films compared of 20-nm-diameter Ag NWs (aspect ratio: ～1000).