Journal of Polymer Science Part B: Polymer Physics, Vol.38, No.8, 1053-1068, 2000
Off-lattice Monte Carlo simulation of the discrete Edwards model
Recently, we used discrete off-lattice versions of the 3D Edwards model in conjunction with Monte Carlo simulations to study polymer brushes and diblock copolymer melts. Here we show by numerical simulation that the discrete Edwards model gives the scaling and corrections-to-scaling properties appropriate for a single polymer under good solvent conditions. This in addition provides justification for the use of Edwards-type models in our earlier Monte Carlo simulations of dense systems. To this end, we studied a discrete off-lattice version of the 3D Edwards model for a single polymer under good solvent conditions by Monte Carlo simulation. We analyze sampled distribution functions of the end-to-end distance for chain lengths N = 10, 100, 237, and find them in good agreement with an ansatz suggested by Redner and des Cloizeaux. From simulation data for the end-to-end distance, R-e, and the radius of gyration, R-g, as a function of N, we then determine best-fit values for the critical exponent nu and the first nonanalytical correction-to-scaling exponent Delta(1), from the ansatz (R-x(2)) = A(x)N(2 nu)(1 + BxN-Delta 1 + CxN-1) with x = e, g. The results nu = 0.596 +/- 0.007 and Delta(1) = 0.43 +/-0.05 are in good agreement with estimates derived in other simulation studies. These findings show that Monte Carlo simulations using the discrete 3D Edwards model do indeed give a reliable description of the behavior of a single polymer in a good solvent as N --> infinity. This vindicates our simulational approach in using discrete Edwards-type models for the study of conformational properties of many polymer systems.
Keywords:polymer in good solvent;radius of gyration;end-to-end distance;self-avoiding random walk;scaling;corrections-to-scaling;scaling exponents;distribution functions;Monte Carlo simulation;discrete Edwards model