The theta condition for linear polymer chains in continuous space and three dimensions

Yong, C. W.; Clarke, Julian H. R.; Freire, Juan J.; Bishop, Marvin
December 1996
Journal of Chemical Physics;12/1/1996, Vol. 105 Issue 21, p9666
Academic Journal
Configurational properties of isolated flexible linear chains of lengths in the range 72≤N≤576 have been investigated close to the theta regime by continuous space simulations using a configurational bias Monte Carlo algorithm. The polymer model consisted of beads interacting through a nontruncated Lennard-Jones potential and connected by a Gaussian distribution of link vectors. We use two criteria in order to characterize departures from ideal behavior at finite N, first the ratio of the mean squared end-to-end distance and the mean squared radius of gyration, and second the end-to-end vector distribution. Both the criteria lead, within the statistical errors, to the same prediction for the theta temperature as N→∞; the ratio criterion gives k[sub B]T[sub θ][sup rat]/ε=4.167±0.035 and the distribution criterion gives k[sub B]T[sub θ][sup dis]/ε=4.184±0.035, in close agreement with previous estimates for the same model. Deviations from ideal behavior were found to be independent of whether the finite number of beads constitute a whole chain or merely an inner part of a much larger chain. The N-dependencies of several configurational properties including the moments of the end-to-end distribution and the asphericity have been examined at the N→∞ theta temperature. Nonideal effects are manifest in different ways dependent on the property being considered. For instance the radius of gyration shows a slight contraction effect which diminishes with increasing chain length and which shows remarkable quantitative agreement with the prediction of tricritical renormalization group theory, while the end-to-end distribution shows slight expansion effects. It is suggested that each property emphasizes nonideal effects in slightly different ways. © 1996 American Institute of Physics.


Related Articles

  • Continuous time simulation of transient polymer network models. Biller, Peter; Petruccione, Francesco // Journal of Chemical Physics;5/15/1990, Vol. 92 Issue 10, p6322 

    A continuous time simulation algorithm for polymer melts is presented. The method is introduced via an explicit application to transient polymer network models, but it may be applied to a much larger class of models. The central quantity of the simulation is the lifetime of a strand. This can be...

  • Monte Carlo simulation of homopolymer melts in plane Poiseuille flow. Gleiman, Seth S.; Dorgan, John R. // Journal of Chemical Physics;4/1/2000, Vol. 112 Issue 13 

    A special biased Monte Carlo algorithm is used to study flow of homopolymer melts between neutral, hard walls on a fcc lattice at full occupancy (φ=1). A random number biasing technique is developed to mimic slot flow of a melt; the biasing method preferentially moves the chains in the...

  • Monte Carlo study of associative polymer networks. I. Equation of state. Groot, Robert D.; Agterof, Wim G. M. // Journal of Chemical Physics;1/15/1994, Vol. 100 Issue 2, p1649 

    The equation of state of associative polymer networks has been studied by Monte Carlo simulation. To describe the associations, an algorithm is introduced which for dilute monatomic systems reduces to the well-known mass action law. For the polymers, the simple bead spring model was employed....

  • Hybrid Monte Carlo simulation of polymer chains. Irbäck, A. // Journal of Chemical Physics;7/15/1994, Vol. 101 Issue 2, p1661 

    We develop the hybrid Monte Carlo method for simulations of single off-lattice polymer chains. We discuss implementation and choice of simulation parameters in some detail. The performance of the algorithm is tested on models for homopolymers with short- or long-range self-repulsion, using...

  • Detailed atomistic Monte Carlo simulation of grafted polymer melts: II. Orientational order and nuclear magnetic resonance spectra. Daoulas, Kostas Ch.; Mavrantzas, Vlasis G.; Photinos, Demetri J. // Journal of Chemical Physics;1/15/2003, Vol. 118 Issue 3, p1521 

    We present results on the profiles of the first- and second-rank bond-order parameters, 〈P[sub 1](cos θ)〉 and 〈P[sub 2](cos θ)〉, of the grafted polymer melts simulated in atomistic detail in Part I of this work, with the end-bridging Monte Carlo (EBMC) algorithm....

  • Swelling of two-dimensional polymer rings by trapped particles. Haleva, E.; Diamant, H. // European Physical Journal E -- Soft Matter;Sep2006, Vol. 21 Issue 1, p33 

    The mean area of a two-dimensional Gaussian ring of N monomers is known to diverge when the ring is subject to a critical pressure differential, p c ∼ N -1. In a recent publication (Eur. Phys. J. E 19, 461 (2006)) we have shown that for an inextensible freely jointed ring this divergence...

  • Fluid phase behavior of a model colloid-polymer mixture: Influence of polymer size and interaction strength. Rosch, Thomas W.; Errington, Jeffrey R. // Journal of Chemical Physics;10/28/2008, Vol. 129 Issue 16, p164907 

    We examine how the fluid-fluid phase behavior of a model colloid-polymer mixture evolves with variation of polymer size and/or interaction strength. Polymer-polymer interactions are approximated through Gaussian-core potentials while colloid-colloid and colloid-polymer interactions are assumed...

  • Simulations of Gaussian and Excluded-Volume Chains in Curved Slits. Suzuki, Yasuo Y.; Dotera, Tomonari; Hirabayashi, Megumi // AIP Conference Proceedings;2004, Vol. 708 Issue 1, p257 

    We propose polymer models for Monte Carlo simulation and apply them to a polymer chain confined in a thin box which has both curved and flat sides, and show that either a Gaussian or an excluded-volume chain spends more time in the curved region than in the flat region. The ratio of the...

  • Infinite-Dimensional Quadrature and Approximation of Distributions. Creutzig, Jakob; Dereich, Steffen; M�ller-Gronbach, Thomas; Ritter, Klaus // Foundations of Computational Mathematics;Aug2009, Vol. 9 Issue 4, p391 

    We study numerical integration of Lipschitz functionals on a Banach space by means of deterministic and randomized (Monte Carlo) algorithms. This quadrature problem is shown to be closely related to the problem of quantization and to the average Kolmogorov widths of the underlying probability...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics