Flory’s interaction parameter

X Flory s interaction parameter related to the polymer-solvent contact energy... 

Flory s interaction parameter between the two species present in the system if there are more than two species one writes Xy where i and j characterize the interacting species. 

As discussed in Chapter 2, the ability of a solvent to dissolve a polymer will depend on the difference in their solubility parameters or on Flory s interaction parameter. The interaction parameter depends on temperature (see Equation 2.13), and therefore the swelling of a coil by a solvent will also depend on temperature. 

Ky is the Flory-Huggins interaction parameter between the i and j monomers. In Eq. 6.6, the matrices have a dimension (m) (m). We note that the s-depen-dence of the excluded volume matrix is solely determined by the contribution of the bare susceptibility yoo(Q> ) he invisible matrix component 0 . Finally, combining Eq. 6.6 with Eq. 6.1 the response function in the interacting system is given by ... 

In addition to the solubility parameter model to treat SEC adsorption effects, an approach based on Flory-Huggins interaction parameters has also been proposed (24-27). For an excellent review of both mechanisms, see reference 28.- A general treatment of polymer adsorption onto chromatographic packings can be found in Belenkii and Vilenchik s recent book (29). 

The Flory-Huggin S Interaction Parameter. These ideas, based on a study of polymer miscibility, have been applied to plasticizers according to the following equation in which V is the molar volume of the plasticizer, obtained from molar mass figures and density values at TV, and % represents the interaction parameter (11). 

The theories of polymer solutions upon which steric-stability theories are based are usually formulated in terms of a portmanteau interaction parameter (for example Flory s X Parameter and the excluded volume integral) which does not preclude electrostatic interactions, particularly under conditions where these are short range. It is thus appropriate to consider whether polyelect-roly te-stabilisation can be understood in the same broad terms as stabilisation by non-ionic polymers. It was this together with the fact that polyelectrolyte solutions containing simple salts show phase-separation behaviour reminiscent of that of non-ionic... 

Let us analyze now the results for the general case when network swells in a solution of linear polymers. Let p, C, be, respectively, the volume fractions of linear polymer and low-molecular solvent in external solution Xps. Xn and Xnp are the Flory-Huggins interaction parameters between linear polymer (P), network polymer (N) and solvent (S). 

Our discussion here explores active connections between the potential distribution theorem (PDT) and the theory of polymer solutions. In Chapter 4 we have already derived the Flory-Huggins model in broad form, and discussed its basis in a van der Waals model of solution thermodynamics. That derivation highlighted the origins of composition, temperature, and pressure effects on the Flory-Huggins interaction parameter. We recall that this theory is based upon a van der Waals treatment of solutions with the additional assumptions of zero volume of mixing and more technical approximations such as Eq. (4.45), p. 81. Considering a system of a polymer (p) of polymerization index M dissolved in a solvent (s), the Rory-Huggins model is... 

Liquid water as contacting medium (dealt as a solvent) interacts with polymer molecules in different degrees some dissolve polymers, some swell polymers, and some are merely adsorbed at the polymer/water interface with no significant alteration of physical properties of polymers. The enthalpy term of the interaction could be represented by Flory-Huggins s interaction parameter x- In order to distinguish the molecular interaction from the interfacial interaction, the molecular interaction could be termed x interaction and the interfacial interaction y interaction. When a solid polymer is in contact with water (solvent), the extent of x interaction depends on the hydrophilicity or hydrophobicity of the polymer. However, the interfacial phenomena generally cannot be interpreted by molecular level parameters that describe the bulk phase of a polymer such as hydrophilicity or hydrophobicity. 

JAN Janssen, S., Schwahn, D., Mortensen, K., and Springer, T., Pressure dependence of the Flory-Huggins interaction parameter in polymer blends. A SANS study and a comparison to the Floty-Orwoll-Vrij equation of state (experimental data by S. Janssen), Macromolecules,... 

Flory-Huggins interaction parameter versus weight fraction of PVA in PVA/chitosan blends. (From Jawalkar, S. S., Raju, K. V. S. N., Halligudi, S. B., Sairam, M., and Aminabhavi, T. M. 2007. Molecular modeling simulations to predict compatibility of poly(vinyl alcohol) and chitosan blends A comparison with experiments. Journal of Physical Chemistry B 111 2431-2439.)... 

MO2 Morariu, S., Nichifor, M., Eckelt, J., and Wolf, B.A., Dextran-based polycations Thermodynamic interaction with water as compared with unsubstituted dextran, 2 -Flory/Huggins interaction parameter, Macrowo/. Chem. Phys., 212, 1932, 2011. 

Symbols with a tilde are scaled [189]. Note that d depends on the reduced independent variables, P and T. Minimization of the entropic contribution to the Huggins-Flory binary interaction parameter leads to Hildebrand s dependence ... 

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