English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Semiflexible macromolecules in dilute solution under very good solventconditions are modeled by self-avoiding walks on the simple cubic lattice($d=3$ dimensions) and square lattice ($d=2$ dimensions), varying chainstiffness by an energy penalty $\epsilon_b$ for chain bending. In the absenceof excluded volume interactions, the persistence length $\ell_p$ of thepolymers would then simply be $\ell_p=\ell_b(2d-2)^{-1}q_b^{-1}$ with $q_b=\exp(-\epsilon_b/k_BT)$, the bond length $\ell_b$ being the lattice spacing,and $k_BT$ is the thermal energy. Using Monte Carlo simulations applying thepruned-enriched Rosenbluth method (PERM), both $q_b$ and the chain length $N$are varied over a wide range $(0.005 \leq q_b \leq 1, \; N \leq 50000$), andalso a stretching force $f$ is applied to one chain end (fixing the other endat the origin). In the absence of this force, in $d=2$ a single crossover fromrod-like behavior (for contour lengths less than $\ell_p$) to swollen coilsoccurs, invalidating the Kratky-Porod model, while in $d=3$ a double crossoveroccurs, from rods to Gaussian coils (as implied by the Kratky-Porod model) andthen to coils that are swollen due to the excluded volume interaction. If thestretching force is applied, excluded volume interactions matter for the forceversus extension relation irrespective of chain stiffness in $d=2$, whiletheories based on the Kratky-Porod model are found to work in $d=3$ for stiffchains in an intermediate regime of chain extensions. While for $q_b \ll 1$ inthis model a persistence length can be estimated from the initial decay ofbond-orientational correlations, it is argued that this is not possible formore complex wormlike chains (e.g. bottle-brush polymers). Consequences for theproper interpretation of experiments are briefly discussed.

Stretching Semiflexible Polymer Chains: Evidence for the Importance of Excluded Volume Effects from Monte Carlo Simulation