Thermodynamic model, swelling

In summary, the thermodynamic Model I based on Morton s theory has been used to successfully fit experimental data and obtain semi-empirical equations for the swelling of polystyrene and polymethyl methacrylate latexes. The semi-empirical equations offer a quick method for estimating swelling ratio from particle size and interfacial tension. The generalized form of Model II might prove to be more suitable for describing the swelling phenomena of relatively hydrophilic systems. ... 

Chen et al. [39] and Jonsson et al. 140,41] independently proved that the composite particle morphology could be brought towards the equilibrium morphology predicted by the thermodynamic model by a post-polymerization swelling treatment of the composite latexes with solvents. 

W12 Wissinger, R.G. and Paulaitis, M.E., Molecular thermodynamic model for sorption and swelling in glassy polymer-C02 systems at elevated pressnres, Ind. Eng. Chem. Res., 29, 842, 1991. 

The above discussed thermodynamic model for describing, explaining and predicting monomer partitioning during emulsion polymerisation has also been successfully applied to the swelling of phospholipid bHayers by an organic solvent (Maxwell et al, 1995). 

Mauritz et al., motivated by these experimental results, developed a statistical mechanical, water content and cation-dependent model for the counterion dissociation equilibrium as pictured in Figure 12. This model was then utilized in a molecular based theory of thermodynamic water activity, aw, for the hydrated clusters, which were treated as microsolutions. determines osmotic pressure, which, in turn, controls membrane swelling subject to the counteractive forces posed by the deformed polymer chains. The reader is directed to the original paper for the concepts and theoretical ingredients. 

The constitutive equations use a thermodynamic framework, that in fact embodies not only purely mechanical aspects, but also transfers of masses between the phases and diffusion of matter through the extrafibrillar phase. Since focus is on the chemo-mechanical couplings, we use experimental data that display different salinities. The structure of the constitutive functions and the state variables on which they depend are briefly motivated. Calibration of material parameters is defined and simulations of confined compression tests and of tree swelling tests with a varying chemistry are described and compared with available data in [3], The evolution of internal entities entering the model, e.g. the masses and molar fractions of water and ions, during some of these tests is also documented to highlight the main microstructural features of the model. 

By combining thermodynamically-based monomer partitioning relationships for saturation [170] and partial swelling [172] with mass balance equations, Noel et al. [174] proposed a model for saturation and a model for partial swelling that could predict the mole fraction of a specific monomer i in the polymer particles. They showed that the batch emulsion copolymerization behavior predicted by the models presented in this article agreed adequately with experimental results for MA-VAc and MA-Inden (Ind) systems. Karlsson et al. [176] studied the monomer swelling kinetics at 80 °C in Interval III of the seeded emulsion polymerization of isoprene with carboxylated PSt latex particles as the seeds. The authors measured the variation of the isoprene sorption rate into the seed polymer particles with the volume fraction of polymer in the latex particles, and discussed the sorption process of isoprene into the seed polymer particles in Interval III in detail from a thermodynamic point of view. 

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