Depletion effects in colloid-polymer solutions

Abstract

The surface tension, the adsorption, and the depletion thickness of polymers close to a single nonadsorbing colloidal sphere are computed by means of Monte Carlo simulations. We consider polymers under good-solvent conditions and in the thermal crossover region between good-solvent and $\theta$ behavior. In the dilute regime we consider a wide range of values of $q$, from $q=0$ (planar surface) up to $q\approx 30$-50, while in the semidilute regime, for ${\rho }_p/{\rho }_p^{\ast }\le 4$ (${\rho }_p$ is the polymer concentration and ${\rho }_p^{\ast }$ is its value at overlap), we only consider $q=0,0.5,1$ and 2. The results are compared with the available theoretical predictions, verifying the existing scaling arguments. Field-theoretical results, both in the dilute and in the semidilute regime, are in good agreement with the numerical estimates for polymers under good-solvent conditions.

26 pages, 12 figures

References in corpus (7)

• Accurate estimate of the critical exponent $\nu$ for self-avoiding walks via a fast implementation of the pivot algorithm
• A multi-blob representation of semi-dilute polymer solutions
• Virial coefficients and osmotic pressure in polymer solutions in good-solvent conditions
• Polymers as compressible soft spheres
• Influence of solvent quality on polymer solutions: a Monte Carlo study of bulk and interfacial properties
• Third virial coefficient for 4-arm and 6-arm star polymers
• Two-parameter model predictions and theta-point crossover for linear-polymer solutions

Cited by in corpus (1)

• Accurate coarse-grained models for mixtures of colloids and linear polymers under good-solvent conditions