Phase behaviour of model polymeric networks and gels

Results of Monte Carlo simulations are presented for the volumetric properties of pure model networks consisting of both hard-core and square-well interaction sites. Evidence of a phase transition is reported for pure square-well networks at negative pressures. An off-lattice, mean-field model is developed and shown to be capable of describing the simulated phase diagram of square-well networks and the equilibrium swelling of athermal gels. Increasing the pressure or the strand length is found to lead to higher solvent uptake by the gel.