Friction of single polymers at surfaces.
Atomic force microscope (AFM) single molecule force spectroscopy has been used to investigate the friction coefficient of individual polymers adsorbed onto a solid support. The polymer chains were covalently attached to an AFM tip and were allowed to adsorb on a mica surface. Different polymers (ssDNA, polyallylamine) were chosen to cover a range of friction coefficients. During the experiment, the AFM tip was retracted in- and off-plane which results, depending on the chosen conditions, in a desorption of the polymer from the surface, a sliding across the surface, or a combination of both. Thus, the obtained force-extension spectra reveal detailed information on the mobility of a polymer chain on a surface under experimentally accessible conditions. This study demonstrates that absorbed polymers with comparable desorption forces may exhibit drastically different in plane mobility.
Kühner
Ferdinand
F
Chair for Applied Physics and Center for NanoScience, Ludwig Maximillians Universität, Munich, Germany. Ferdinand.Kuehner@lmu.de
Erdmann
Matthias
M
Sonnenberg
Lars
L
Serr
Andreas
A
Morfill
Julia
J
Gaub
Hermann E
HE
D000265:Adenylosuccinate Synthase; D004277:DNA, Single-Stranded; D017276:Friction; D008422:Materials Testing / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods; D011073:Polyamines
D004277:DNA, Single-Stranded; D011073:Polyamines; C063994:polyallylamine; C503206:ADSS1 protein, human; D000265:Adenylosuccinate Synthase