title: Perimeter length and form factor in two-dimensional polymer melts.
abstract: Self-avoiding polymers in two-dimensional (d=2) melts are known to adopt compact configurations of typical size R(N) approximately N;{1/d} , with N being the chain length. Using molecular-dynamics simulations we show that the irregular shapes of these chains are characterized by a perimeter length L(N) approximately R(N);{d_{p}} of fractal dimension d_{p}=d-Theta_{2}=5/4 , with Theta_{2}=3/4 being a well-known contact exponent. Due to the self-similar structure of the chains, compactness and perimeter fractality repeat for subchains of all arclengths s down to a few monomers. The Kratky representation of the intramolecular form factor F(q) reveals a strong nonmonotonous behavior with q;{2}F(q) approximately 1/(qN;{1/d});{Theta_{2}} in the intermediate regime of the wave vector q . Measuring the scattering of labeled subchains the form factor may allow to test our predictions in real experiments.
authors.affiliation: Institut Charles Sadron, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France.
authors.forename: H
authors.initials: H
authors.lastname: Meyer
authors.forename: T
authors.initials: T
authors.lastname: Kreer
authors.forename: M
authors.initials: M
authors.lastname: Aichele
authors.forename: A
authors.initials: A
authors.lastname: Cavallo
authors.forename: A
authors.initials: A
authors.lastname: Johner
authors.forename: J
authors.initials: J
authors.lastname: Baschnagel
authors.forename: J P
authors.initials: JP
authors.lastname: Wittmer