Silica segmental adsorption energy

Determination of the segmental adsorption energy. The determina-tion of x ° is also possible. Since x d can be found from Equation 5 if Xsc an the solvency terms are known, we can add xf° and find x ° by Equation 1. The determination of xf° calls for a separate experiment, e.g., an adsorption isotherm of the displacer from solvent, in the absence of polymer. Following such a scheme we used the values of cr obtained from the displacement isotherms of Figure 3 and 4 to determine segmental adsorption energy parameters Xg° for PVP on silica. The required additional information on xdo was obtained from the initial slopes of dis-... 

Cohen Stuart, M. A., Fleer, G. J., Scheutjens, J. M. H. M. 1984. Displacement of polymers. II. Experiment. Determination of segmental adsorption energy of poly(vinylpyrrolidone) on silica. l ColLJnt Sd. 97 526-535. 

There continues to be extensive interest in latexes and micellar systems. The structure of acrylic latex particles has been investigated by non-radiative energy transfer by labelling the co-monomers with fluorescent acceptor-donor systems. Phase separations could also be measured in this way. Excimer fluorescence has been used to measure the critical micelle temperature in diblock copolymers of polystyrene with ethylene-propylene and the results agree well with dynamic light scattering measurements. Fluorescence anisotropy has been used to measure adsorption isotherms of labelled polymers to silica as well as segmental relaxation processes in solutions of acrylic polymers. In the latter case unusual interactions were indicated between the polymers and chlorinated hydrocarbon solvents. Fluorescence analysis of hydrophobically modifled cellulose have shown the operation of slow dynamic processes while fluorescence... 

---