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

## Abstract

A coarse-graining strategy, previously developed for polymer solutions, is extended here to mixtures of linear polymers and hard-sphere colloids. In this approach, groups of monomers are mapped onto a single pseudoatom (a blob) and the effective blob-blob interactions are obtained by requiring the model to reproduce some large-scale structural properties in the zero-density limit. We show that an accurate parametrization of the polymer-colloid interactions is obtained by simply introducing pair potentials between blobs and colloids. For the coarse-grained (CG) model in which polymers are modelled as four-blob chains (tetramers), the pair potentials are determined by means of the iterative Boltzmann inversion scheme, taking full-monomer (FM) pair correlation functions at zero-density as targets. For a larger number n of blobs, pair potentials are determined by using a simple transferability assumption based on the polymer self-similarity. We validate the model by comparing its predictions with full-monomer results for the interfacial properties of polymer solutions in the presence of a single colloid and for thermodynamic and structural properties in the homogeneous phase at finite polymer and colloid density. The tetramer model is quite accurate for q ≲ 1 (q=R{sup ^}{sub g}/R{sub c}, where R{sup ^}{sub g} is the zero-density polymer radius of gyrationmore »

- Authors:

- SISSA, V. Bonomea 265, I-34136 Trieste (Italy)
- Dipartimento di Fisica, Sapienza Università di Roma and INFN, Sezione di Roma I, P.le Aldo Moro 2, I-00185 Roma (Italy)
- Dipartimento di Scienze Fisiche e Chimiche, Università dell’Aquila and CNISM, UdR dell’Aquila, V. Vetoio 10, Loc. Coppito, I-67100 L’Aquila (Italy)

- Publication Date:

- OSTI Identifier:
- 22410267

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CHAINS; COLLOIDS; CORRELATION FUNCTIONS; DENSITY; FORECASTING; INTERACTIONS; ITERATIVE METHODS; MONOMERS; POLYMERS; SOLUTIONS; SOLVENTS

### Citation Formats

```
D’Adamo, Giuseppe, E-mail: giuseppe.dadamo@sissa.it, Pelissetto, Andrea, E-mail: andrea.pelissetto@roma1.infn.it, and Pierleoni, Carlo, E-mail: carlo.pierleoni@aquila.infn.it.
```*Accurate coarse-grained models for mixtures of colloids and linear polymers under good-solvent conditions*. United States: N. p., 2014.
Web. doi:10.1063/1.4904392.

```
D’Adamo, Giuseppe, E-mail: giuseppe.dadamo@sissa.it, Pelissetto, Andrea, E-mail: andrea.pelissetto@roma1.infn.it, & Pierleoni, Carlo, E-mail: carlo.pierleoni@aquila.infn.it.
```*Accurate coarse-grained models for mixtures of colloids and linear polymers under good-solvent conditions*. United States. doi:10.1063/1.4904392.

```
D’Adamo, Giuseppe, E-mail: giuseppe.dadamo@sissa.it, Pelissetto, Andrea, E-mail: andrea.pelissetto@roma1.infn.it, and Pierleoni, Carlo, E-mail: carlo.pierleoni@aquila.infn.it. Sun .
"Accurate coarse-grained models for mixtures of colloids and linear polymers under good-solvent conditions". United States.
doi:10.1063/1.4904392.
```

```
@article{osti_22410267,
```

title = {Accurate coarse-grained models for mixtures of colloids and linear polymers under good-solvent conditions},

author = {D’Adamo, Giuseppe, E-mail: giuseppe.dadamo@sissa.it and Pelissetto, Andrea, E-mail: andrea.pelissetto@roma1.infn.it and Pierleoni, Carlo, E-mail: carlo.pierleoni@aquila.infn.it},

abstractNote = {A coarse-graining strategy, previously developed for polymer solutions, is extended here to mixtures of linear polymers and hard-sphere colloids. In this approach, groups of monomers are mapped onto a single pseudoatom (a blob) and the effective blob-blob interactions are obtained by requiring the model to reproduce some large-scale structural properties in the zero-density limit. We show that an accurate parametrization of the polymer-colloid interactions is obtained by simply introducing pair potentials between blobs and colloids. For the coarse-grained (CG) model in which polymers are modelled as four-blob chains (tetramers), the pair potentials are determined by means of the iterative Boltzmann inversion scheme, taking full-monomer (FM) pair correlation functions at zero-density as targets. For a larger number n of blobs, pair potentials are determined by using a simple transferability assumption based on the polymer self-similarity. We validate the model by comparing its predictions with full-monomer results for the interfacial properties of polymer solutions in the presence of a single colloid and for thermodynamic and structural properties in the homogeneous phase at finite polymer and colloid density. The tetramer model is quite accurate for q ≲ 1 (q=R{sup ^}{sub g}/R{sub c}, where R{sup ^}{sub g} is the zero-density polymer radius of gyration and R{sub c} is the colloid radius) and reasonably good also for q = 2. For q = 2, an accurate coarse-grained description is obtained by using the n = 10 blob model. We also compare our results with those obtained by using single-blob models with state-dependent potentials.},

doi = {10.1063/1.4904392},

journal = {Journal of Chemical Physics},

number = 24,

volume = 141,

place = {United States},

year = {Sun Dec 28 00:00:00 EST 2014},

month = {Sun Dec 28 00:00:00 EST 2014}

}