Dynamic Monte Carlo study on the polymer chain in random media filled with nanoparticles

The effect of nanoparticles on the dynamic and configurational properties of a single polymer chain has been studied by using dynamic Monte Carlo simulation. An attractive potential, ε, is considered between fixed nanoparticles and polymer beads. The diffusion coefficient of the polymer D remains constant for weak interactions, i.e. small β=−ε/kBT, and then gradually drops to zero at a critical value βD*. However, the mean square end-to-end distance 〈R2〉 shows a different behavior with an increase in the attractive interaction. 〈R2〉 decreases at small β and reaches a minimum at βR*, then goes up slowly and at last saturates at strong interaction. The values βD* and βR* scale with the concentration of nanoparticles. Interesting findings are: (1) a chain has its minimum size before the chain stops its diffusion, and (2) a chain continues its configuration adjustment even for β>βD*.