Force-extension curve of a polymer in a high-frequency electric field.
We study theoretically the conformation and force-extension curve of a semiflexible polymer in a spatially uniform ac electric field. The polymer backbone minimizes its energy by aligning along one of two orientations parallel to the field. In a strong ac field, hairpin kinks develop between regions of opposite alignment. These kinks are mathematically described as sine-Gordon solitons. We calculate the equation of state of the one-dimensional kink gas, which yields the force-extension curve of the polymer. A sufficiently strong ac field causes the polymer to extend spontaneously to almost its full contour length. The theory is applied to recent experiments on dielectrophoretic stretching of DNA.
Cohen
Adam E
AE
Department of Physics, 382 Via Pueblo Mall, Stanford University, Stanford, California 94305-4060, USA. acohen@post.harvard.edu
D004247:DNA / Q000737:chemistry*; D004574:Electromagnetic Fields; D008956:Models, Chemical; D008968:Molecular Conformation; D009690:Nucleic Acid Conformation; D011108:Polymers / Q000737:chemistry*; D013816:Thermodynamics
D011108:Polymers; D004247:DNA