Orientation of Polymer Chains in Dilute Solution under Shear: Effect of Chain Model and Excluded Volume

✍ Scribed by José G. Hernández Cifre; José García de la Torre

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 122 KB
• Volume: 13
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/mats.200300023

✦ Synopsis

Abstract

Summary: Polymer orientation in dilute solutions undergoing shear flow is investigated computationally by means of the Brownian dynamics simulation technique applied to the bead‐spring chain model. The dependence of the degree of orientation on the shear intensity is evaluated through a quantity called orientation resistance. All simulations were performed using non‐preaveraged hydrodynamic interaction (HI). The spring type (Gaussian or FENE) is shown to strongly determine the shear flow behavior of the chain orientation. Solvent quality (Θ, good or bad), represented by a suitable Lennard‐Jones intramolecular potential, does not affect the flow behavior but influences the values of the orientation resistance. Hence, the orientability of the polymer molecule is, in a way, related to the flow intensity.

Evolution of m~G~ (orientational resistance parameter, open circles are simulation, dashed line is Gaussian approximation) and m~τ~ (filled circles are simulation, dotted line is Gaussian approximation) with β for ideal Gaussian chains with N = 15.

imageEvolution of m~G~ (orientational resistance parameter, open circles are simulation, dashed line is Gaussian approximation) and m~τ~ (filled circles are simulation, dotted line is Gaussian approximation) with β for ideal Gaussian chains with N = 15.