First observation of mechanochromism at the nanometer scale
First observation of mechanochromism at the nanometer scale
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DOI：
10.1021/la990706a
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发表时间：
2000-02-08
期刊：
影响因子：
3.9
通讯作者：
Burns, AR
中科院分区：
文献类型：
--
作者：
Carpick, RW;Sasaki, DY;Burns, AR
使用两种不同的扫描探针显微镜的尖端，在聚丁二炔薄膜中产生了纳米尺度的机械诱导颜色转变（“机械变色”）。用近场扫描光学显微镜和原子力显微镜（AFM）分别观察到，由10，12-二十五碳二炔酸（poly-PCDA）聚合而成的聚丁二炔分子三层膜中的蓝-红颜色转变是由于探针与poly-PCDA分子之间的剪切力引起的。用AFM观察到宽度小至30 nm的转化区域。不可逆转化的域优先沿聚合物主链方向沿着生长。通过AFM在转化区域中观察到聚PCDA双层片段的显著重排。这些部分的重新排列似乎是过渡的一个特征。据我们所知，这是首次在任何材料中观察到纳米尺度的机械致色性。
A mechanically induced color transition ("mechanochromism") in poly(diacetylene) thin films has been generated at the nanometer scale using the tips of two different scanning probe microscopes. A blue-to-red chromatic transition in poly(diacetylene) molecular trilayer films, polymerized fr om 10,12-pentacosadiynoic acid (poly-PCDA), was found to result from shear forces acting between the tip and the poly-PCDA molecules, as independently observed with near-field scanning optical microscopy and atomic force microscopy (AFM), Red domains were identified by a fluorescence emission signature. Transformed regions as small as 30 nm in width were observed with AFM. The irreversibly transformed domains preferentially grow along the polymer backbone direction. Significant rearrangement of poly-PCDA bilayer segments is observed by AFM in transformed regions. The rearrangement of these segments appears to be a characteristic feature of the transition. To our knowledge, this is the first observation of nanometer-scale mechanochromism in any material.