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Nanoscience of single polymer chains revealed by nanofishing
Author(s) -
Nakajima Ken,
Nishi Toshio
Publication year - 2006
Publication title -
the chemical record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.61
H-Index - 78
eISSN - 1528-0691
pISSN - 1527-8999
DOI - 10.1002/tcr.20092
Subject(s) - polymer , viscoelasticity , polystyrene , materials science , elasticity (physics) , viscosity , solvent , polymer science , polymer chemistry , chemical physics , nanotechnology , chemistry , composite material , organic chemistry
The invention of atomic force microscopy (AFM) enabled us to study the statistical properties of single polymer chains by a method called “nanofishing,” which stretches a single polymer chain adsorbed on a substrate with its one end by picking it at the other end. A force‐extension curve obtained for a single polystyrene chain in a Θ solvent (cyclohexane) shows good agreement with a worm‐like chain model and, therefore, gives microscopic information about entropic elasticity. Furthermore, the nanofishing technique can be used for dynamic viscoelastic measurement of single polymer chains. An AFM cantilever is mechanically oscillated at its resonant frequency during the stretching process. This technique enables the estimation of quantitative and simultaneous elongation‐dependent changes of stiffness and viscosity of a single chain with the use of a phenomenological model. In this study, the effect of solvent on viscosity in low extension regions reveals that the viscosity is attributed to monomer‐solvent friction. Thus, static and dynamic nanofishing techniques are shown to give powerful experimental proofs for several basic questions in polymer physics. The techniques are expected to reveal hidden properties of polymer chains or polymer solutions by any types of macroscopic measurements in the future. © 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 249–258; 2006: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20092