A molecular thermodynamic model for the swelling of thermo-sensitive hydrogels

Thermodynamics of aqueous solutions containing poly (N-isopropylacrylamide)

“…Using this approach the involved phaseand swelling equilibria could be modeled close to the experimental values [11]. Huang et al applied also the SL-EOS [12] to this system, where the swelling equilibrium is described well; however, the EOS models a closed-loop miscibility gap, which was not found experimentally. The reason for this finding is the cubic temperature dependence of the interaction energy.…”

A new thermodynamic model of volume changes in temperature-sensitive polymer gels

“…(23) together with Eq. (22) permits the calculation of the swelling degree of the gel q ¼ r=r B and of the distribution of the gel species B j . In this the normalization condition:…”

“…The mixing term, in the simplest case, can be taken from the Flory-Huggins lattice theory or of a modified version of that. Some authors take into account free volume contributions too [8,9,[16][17][18][19][20][21][22]. There are a few expressions for the elastic term, e.g.…”

“…Some elastic models are discussed by Gusler and Cohen [25]. The most extensively studied polymer gel is the poly(N-isopropylacrylamide) (PNIPAM) gel [3][4][5][6][7][8][9][10][11][12][13][15][16][17][18][19][20][21][22][26][27][28][29][30][31]. These are very different applications.…”

Thermo-chemo-electro-mechanical modeling of polyelectrolyte gels

“…The thermodynamic modeling of thermoresponsive gels, investigated by the equilibrium swelling theory, can be found e.g. in Marchetti et al 14 or in Huang et al 11 Thermoresponsive gels have been studied experimentally by Kumar et al 12 or Caykara et al 2 Polyelectrolyte gels with degressive temperature-dependent behavior are thermally stimulated by Li et al 13 using Flory's mean field theory and the Flory-Huggins lattice theory. Dobrynin 3 gives a review of theoretical and numerical investigations of charged hydrogels; i.e.…”