Stretching an adsorbed polymer globule.
Using molecular dynamic simulation, we study the stretching of an adsorbed homopolymer in a poor solvent with one end held at a distance ze from the substrate. We measure the vertical force f on the end of the chain as a function of the extension ze and the substrate interaction energy w. The force reaches a plateau value at large extensions. In the strong adsorption limit, we show that the plateau value increases linearly in w in good agreement with a theoretical model. In the weak adsorption limit, a polymer globule with a layered structure is formed and elastically deformed when stretched. In both cases a simple theoretical model permits us to predict the relation between the necessary force to fully detach the polymer and its critical extension.
Laboratoire de Physique de la Matière Condensée, UMR 6622, CNRS, Université de Nice Sophia-Antipolis, Parc Valrose, 06108 Nice Cedex 2, France.
Franck
F
Celestini
Thomas
T
Frisch
Xabier
X
Oyharcabal