Shear-induced mechanochromism in polydiacetylene monolayers

被引：39
作者：
Burns, AR
Carpick, RW
Sasaki, DY
Shelnutt, JA
Haddad, R
机构：
[1] Sandia Natl Labs, MS 1413, Albuquerque, NM 87185 USA
[2] Univ New Mexico, Dept Chem Engn, Albuquerque, NM 87131 USA
来源：
TRIBOLOGY LETTERS | 2001年 / 10卷 / 1-2期
基金：
加拿大自然科学与工程研究理事会;
关键词：
atomic force microscopy; friction force microscopy; friction anisotropy; shear force microscopy; nanotribology; polydiacetylenes; LB films; molecular mechanics; conjugated polymers;
D O I：
10.1023/A:1009018110915
中图分类号：
TQ [化学工业];
学科分类号：
0817 ;
摘要：
We use atomic force microscopy to actuate and characterize the nanoscale "mechanochromism" of polydiacetylene monolayers on atomically-flat silicon oxide substrates. We find explicit evidence that the irreversible blue-to-red transformation is caused by shear forces exerted normal to the polydiacetylene polymer backbone. The anisotropic probe-induced transformation is characterized by a significant change in the tilt orientation of the side chains with respect to the surface normal. We discuss preliminary molecular dynamics simulations and electronic structure calculations on twelve-unit polydiacetylene oligomers that allow us to correlate the transformation with bond-angle changes in the conjugated polymer backbone.
引用
收藏
页码：89 / 96
页数：8
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