title: Phase diagram of mixtures of colloids and polymers in the thermal crossover from good to θ solvent.
abstract: We determine the phase diagram of mixtures of spherical colloids and neutral nonadsorbing polymers in the thermal crossover region between the θ point and the good-solvent regime. We use the generalized free-volume theory, which takes into account the polymer-concentration dependence of the depletion thickness and of the polymer compressibility. This approach turns out to be quite accurate as long as q = Rg/Rc ≲ 1 (Rg is the radius of gyration of the polymer and Rc is the colloid radius). We find that, close to the θ point, the phase diagram is not very sensitive to solvent quality, while, close to the good-solvent region, changes of the solvent quality modify significantly the position of the critical point and of the binodals. We also analyze the phase behavior of aqueous solutions of charged colloids and polymers, using the approach proposed by Fortini et al. [J. Phys.: Condens. Matter 17, 7783 (2005)].
authors.affiliation: SISSA, V. Bonomea 265, I-34136 Trieste, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Adamo
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma and INFN, Sezione di Roma I, P.le Aldo Moro 2, I-00185 Roma, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Pelissetto
authors.affiliation: Dipartimento di Scienze Fisiche e Chimiche, Università dell'Aquila and CNISM, UdR dell'Aquila, V. Vetoio 10, Loc. Coppito, I-67100 L'Aquila, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pierleoni
mesh_terms: D003102:Colloids / Q000737:chemistry*; D008956:Models, Chemical; D009010:Monte Carlo Method; D011108:Polymers / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
chemical_list: D003102:Colloids; D011108:Polymers; D012997:Solvents