Kulakov M, Luzinov I, Kornev K G
School of Materials Science and Engineering, Clemson University, 161 Sirrine Hall, Clemson, South Carolina 29634, USA.
Langmuir. 2009 Apr 21;25(8):4462-8. doi: 10.1021/la802489b.
The DC electropolishing process has been applied to the sharpening of tungsten wires in 2 M KOH aqueous solution. Necking of tungsten anodes takes place in the vicinity of the electrolyte-air interface. This results in the creation of two separate wire parts with nanosharp tips. Using image analysis, we demonstrate that the products of electrochemical reactions on the wire surface form a film with distinguishable properties. Experimental estimates of the film density and interfacial tension show that the film is approximately 32 kg/m3 denser than the surrounding electrolyte and that its interfacial tension is approximately sigma approximately 0.2 mN/m. Using these estimates, we show that the film flow is predominantly driven by capillary forces. We hypothesize that the wire necking is caused by a bidirectional film flow originated from Plateau-Rayleigh instability and inherent to cylindrical films and jets.
直流电解抛光工艺已应用于在2M KOH水溶液中对钨丝进行锐化处理。钨阳极在电解质 - 空气界面附近发生颈缩。这导致形成了两个带有纳米尖锐尖端的独立导线部分。通过图像分析，我们证明了导线表面电化学反应的产物形成了具有可区分特性的薄膜。薄膜密度和界面张力的实验估计表明，该薄膜比周围的电解质密度大约32 kg/m³，其界面张力约为σ≈0.2 mN/m。利用这些估计值，我们表明薄膜流动主要由毛细力驱动。我们推测导线颈缩是由源自普拉托 - 瑞利不稳定性且圆柱形薄膜和射流所固有的双向薄膜流动引起的。
