title: Swelling and collapse of polyelectrolyte gels in equilibrium with monovalent and divalent electrolyte solutions.
abstract: The swelling of polyelectrolyte (PE) gels by 1:1 and 2:1 salts is studied via osmotic ensemble Monte Carlo simulations at constant osmotic pressure and electrolyte chemical potential of a reservoir phase in equilibrium with a model PE network. Large molecular weight gels exhibit a remarkable swelling response to small changes in 2:1 salt concentration. Gel collapse is accompanied by the formation of a previously unknown heterogeneous nanostructure, predicted by theory and observed in simulations, consisting of regions dense in monomers coexisting with regions rich in mono- and divalent ions.
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706-1691, USA.
authors.forename: De-Wei
authors.initials: DW
authors.lastname: Yin
authors.forename: Monica
authors.initials: M
authors.lastname: Olvera de la Cruz
authors.forename: Juan J
authors.initials: JJ
authors.lastname: de Pablo
mesh_terms: D004573:Electrolytes; D005782:Gels; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009995:Osmosis; D012996:Solutions
chemical_list: D004573:Electrolytes; D005782:Gels; D012996:Solutions