TY - JOUR

T1 - Hydrodynamic factors for linear and star polymers on lattice under the theta condition

AU - Shida, Kazuhito

AU - Ohno, Kaoru

AU - Kawazoe, Yoshiyuki

AU - Nakamura, Yo

N1 - Funding Information:
We thank Professor Takashi Norisuye of Osaka University for valuable discussions. This work is supported by the Supercomputing Center of IMR Tohoku University.

PY - 2004/3

Y1 - 2004/3

N2 - Monte Carlo calculations were made to evaluate the intrinsic viscosity [η] and hydrodynamic radius RH along with the mean square radius of gyration 〈S2〉 for linear and star polymers with the arm number f=3, 4, 6, and 8 on a simple cubic lattice. For the hydrodynamic calculation, Zimm's method based on the rigid-body approximation was used. The ensemble averages were taken according to the Boltzman factor with the contacting energy between segments, which was chosen to be 0.275 for the theta condition, multiplied by the number of contacts among the chain. The ratios gη≡[η]star/[η]linear and gH≡(RH)star/(RH) linear calculated agreed with experimental data for theta solvent systems within 3.5 and 2.5%, respectively, where the subscripts describe the structure of polymer chain. The hydrodynamic factors Φ and ρ defined by [η]M/(6〈S2〉)3/2 and 〈S 2〉1/2/RH, respectively, with the molecular weight M obtained from the simulation for linear and star polymers with f=4 and 6 were also close to experimental values. It was concluded that most of the error of analytical theories, which fail to predict hydrodynamic properties for star polymers, comes from the preaveraging approximation of the Oseen tensor.

AB - Monte Carlo calculations were made to evaluate the intrinsic viscosity [η] and hydrodynamic radius RH along with the mean square radius of gyration 〈S2〉 for linear and star polymers with the arm number f=3, 4, 6, and 8 on a simple cubic lattice. For the hydrodynamic calculation, Zimm's method based on the rigid-body approximation was used. The ensemble averages were taken according to the Boltzman factor with the contacting energy between segments, which was chosen to be 0.275 for the theta condition, multiplied by the number of contacts among the chain. The ratios gη≡[η]star/[η]linear and gH≡(RH)star/(RH) linear calculated agreed with experimental data for theta solvent systems within 3.5 and 2.5%, respectively, where the subscripts describe the structure of polymer chain. The hydrodynamic factors Φ and ρ defined by [η]M/(6〈S2〉)3/2 and 〈S 2〉1/2/RH, respectively, with the molecular weight M obtained from the simulation for linear and star polymers with f=4 and 6 were also close to experimental values. It was concluded that most of the error of analytical theories, which fail to predict hydrodynamic properties for star polymers, comes from the preaveraging approximation of the Oseen tensor.

KW - Hydrodynamic property

KW - Monte Carlo calculation

KW - Star polymer

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U2 - 10.1016/j.polymer.2003.12.063

DO - 10.1016/j.polymer.2003.12.063

M3 - Article

AN - SCOPUS:0842328667

VL - 45

SP - 1729

EP - 1733

JO - Polymer (United Kingdom)

JF - Polymer (United Kingdom)

SN - 0032-3861

IS - 5

ER -