Adsorption of polymer on an attractive nano-sized particle

The adsorption of a polymer chain on an attractive nano-sized spherical particle is studied by using Monte Carlo simulation. The polymer-particle interaction is treated as Lennard-Jones potential with strength ε _PP. The critical adsorption point ε ^* _PP is estimated from the largest fluctuation of the number of monomers contacted with particle. We find that ε ^* _PP is dependent on the comparison between particle size σ _p and R _G0, the mean radius of gyration of polymer in dilute solution. ε ^* _PP decreases with an increase in σ _p at σ _p  < R _G0 and is independent of σ _p at σ _p  ≥ R _G0. The polymer starts to be adsorbed on particle, and the mean contact time begins to increase at ε ^* _PP. In addition, the structural property characterized by trains, loops, and tails is investigated for polymer contacted with particle. Results show that the structure is dependent on the interaction strength ε _pp. We find that both the number of monomers contacted with the particle and the length of trains increase with ε _pp, whereas lengths of tail and loop decrease with the increase in ε _pp.