6533b7d3fe1ef96bd1260a79

RESEARCH PRODUCT

Linear Dimensions of Adsorbed Semiflexible Polymers: What can be learned about their persistence length?

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Conformations of partially or fully adsorbed semiflexible polymer chains are studied varying both contour length $L$, chain stiffness, $\ensuremath{\kappa}$, and the strength of the adsorption potential over a wide range. Molecular dynamics simulations show that partially adsorbed chains (with ``tails,'' surface attached ``trains,'' and ``loops'') are not described by the Kratky-Porod wormlike chain model. The crossover of the persistence length from its three-dimensional value (${\ensuremath{\ell}}_{p}$) to the enhanced value in two dimensions ($2{\ensuremath{\ell}}_{p}$) is analyzed, and excluded volume effects are identified for $L\ensuremath{\gg}{\ensuremath{\ell}}_{p}$. Consequences for the interpretation of experiments are suggested. We verify the prediction that the adsorption threshold scales as ${\ensuremath{\ell}}_{p}^{\ensuremath{-}1/3}$.