Mechanochromism, Shear Force Anisotropy, and Molecular Mechanics in Polydiacetylene Monolayers
- Sandia National Laboratories
The authors use scanning probe microscopy to actuate and characterize the nanoscale mechanochromism of polydiacetylene monolayer on atomically-flat silicon oxide substrates. They 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. They also describe a new technique, based on shear force microscopy, that allows them to image friction anisotropy of polydiacetylene monolayer independent of scan direction. Finally, they discuss preliminary molecular mechanics modeling and electronic structure calculations that allow them to understand the correlation of mechanochromism with bond-angle changes in the conjugated polymer backbone.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 761940
- Report Number(s):
- SAND2000-2057J
- Journal Information:
- Tribology Letters, Journal Name: Tribology Letters
- Country of Publication:
- United States
- Language:
- English
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Large Friction Anisotropy of a Polydiacetylene Monolayer
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Related Subjects
ANISOTROPY
ATOMIC FORCE MICROSCOPY
BOND ANGLE
CONJUGATED POLYMERS
ELECTRONIC STRUCTURE
FRICTION
FRICTION ANISOTROPY
FRICTION FORCE MICROSCOPY
MOLECULAR MECHANICS
NANOTRIBOLOGYP
ORGANIC POLYMERS
PHASE TRANSFORMATIONS
POLYDIACETYLENES
LB FILMS
POLYMERS
SHEAR FORCE MICROSCOPY
SILICON OXIDES
SURFACE PROPERTIES
TRIBOLOGY