Laboratório de Nanoestruturas e Interfaces, Instituto de Fisica, UNICAMP, 13083-970, Campinas, SP, Brazil.
Nanotechnology. 2011 Apr 22;22(16):165304. doi: 10.1088/0957-4484/22/16/165304. Epub 2011 Mar 11.
Nanochannels of the order of 20 nm in diameter and forming arrangements that were a few micrometres wide were fabricated on nanometre-thick ice-like deposits on planar mica surfaces at room temperature. Because an atomic force microscopy tip can write lines on ice-like layers covering mica substrates in air that are stable under invariant conditions of humidity and temperature, the water films were modulated with nanochannels. By analysing the shape and morphology of the material removed after channel fabrication for various time intervals, the channel profile was shown to vary with a scale of a tenth of a second. In this configuration (hydrophobic tip and hydrophilic substrate, 65% RH), at the channel top region there were only aggregates of loose flakes formed after the film inscription but no liquid. Apparently, the Kelvin effect is responsible for the nanochannel profile variation with time, but the calculated and measured values of the drainage time constant are at variance by six orders of magnitude. This reduction of the mass transfer is associated with the small dimensions of the ∼ 10 nm-wide channels.
在室温下，于云母平面基底上的纳米级冰状沉积物上制造出直径约 20nm 且排列成数微米宽的纳米通道。由于原子力显微镜探针可以在湿度和温度不变的条件下在覆盖云母基底的冰状层上书写稳定的线条，因此可以对水膜进行纳米通道调制。通过分析通道制造后不同时间段的材料的形状和形态，发现通道的轮廓随时间变化的尺度为十分之一秒。在这种配置中（疏水尖端和亲水基底，65%RH），在通道顶部区域，只有在薄膜刻蚀后形成的松散薄片的聚集，而没有液体。显然，开尔文效应是导致纳米通道轮廓随时间变化的原因，但计算值和测量值的排水时间常数相差六个数量级。这种质量传递的减少与约 10nm 宽的通道的小尺寸有关。
