Polymer adsorption at the

Smith [113] studied the adsorption of n-pentane on mercury, determining both the surface tension change and the ellipsometric film thickness as a function of the equilibrium pentane pressure. F could then be calculated from the Gibbs equation in the form of Eq. ni-106, and from t. The agreement was excellent. Ellipsometry has also been used to determine the surface compositions of solutions [114,115], as well polymer adsorption at the solution-air interface [116]. 

Polymer Adsorption at the Lower Critical Solution Temperature and Its Effect on Colloid Stability... 

In the various sections of this chapter, I will briefly describe the major characteristics of FT-IR, and then relate the importance of these characteristics to physiochemical studies of colloids and interfaces. This book is divided into two major areas studies of "bulk" colloidal aggregates such as micelles, surfactant gels and bilayers and studies of interfacial phenomena such as surfactant and polymer adsorption at the solid-liquid interface. This review will follow the same organization. A separate overview chapter addresses the details of the study of interfaces via the attenuated total reflection (ATR) and grazing angle reflection techniques. 

IV. AGGREGATE FRAGMENTATION INDUCED BY POLYMER ADSORPTION AT THE SOLID/LIQUID INTERFACE... 

In order to understand the role of polymers in their various surface and colloidal applications, it is necessary to understand when, where, why, and how they adsorb at interfaces. While the interactions that control polymer adsorption at the monomer level are the same as those for any monomolecular species, the size of the polymer molecule introduces many complications of analysis that must be treated in a statistical manner, which means that we seldom really know what the situation is but must make educated guesses on the basis of the best available evidence. 

For polar crystalline-amorphous polymers adsorption at the polymer-carrier gas interface becomes much more likely and the contribution of adsorption should be subtracted from the experimental specific retention volume both above and below In-... 

I. Caucheteux, H. Hervet, F. Rondelez, L. Auvray, and J. P. Connon, Polymer adsorption at the solid-liquid interface the interfacial concentration profile, in New Trends in Physics and Physical Chemistry of Polymers (L. H. Lee, ed.). Plenum Press, New York (1989). 

When the maeromolecule is flexible, its deformation takes place at adsorption. One ean observe the change in the number of chain links bound with the surface (Fig. 29) and the surfaee area blockaded by one macromolecule. The rate of ehange of the fraction of bound links is close to the rate of polymer adsorption at the slow stage and the rate of polymer desorption. Therefore, these three processes are boimd to one another and their rates are limited by the rate of macromolecule deformation in the adsorption layer or its flexibility [72]. 

Fig. 2. Schematic representation of the potential seen by the neutron, in the case of strong polymer adsorption at the interface (see Fig. 1).

Comparison between Figs. 5 and 6 also suggests that the bulk concentrations 4> introduced in the calculation of kc)i could have been underestimated. However, even this interpretation cannot explain all observed features of the experimental result. Therefore, the data shown in Fig. 5 reveal information on the polymer concentration profile due to the polymer adsorption at the solution-air interface. This remains to be determined more precisely. 

Of particular interest has been the study of the polymer configurations at the solid-liquid interface. Beginning with lattice theories, early models of polymer adsorption captured most of the features of adsorption such as the loop, train, and tail structures and the influence of the surface interaction parameter (see Refs. 57, 58, 62 for reviews of older theories). These lattice models have been expanded on in recent years using modem computational methods [63,64] and have allowed the calculation of equilibrium partitioning between a poly-... 

Additives. Because of their versatility, imparted via chemical modification, the appHcations of ethyleneimine encompass the entire additive sector. The addition of PEI to PVC plastisols increases the adhesion of the coatings by selective adsorption at the substrate surface (410). PEI derivatives are also used as adhesion promoters in paper coating (411). The adducts formed from fatty alcohol epoxides and PEI are used as dispersants and emulsifiers (412). They are able to control the viscosity of dispersions, and thus faciHtate transport in pipe systems (413). Eatty acid derivatives of PEI are even able to control the viscosity of pigment dispersions (414). The high nitrogen content of PEIs has a flame-retardant effect. This property is used, in combination with phosphoms compounds, for providing wood panels (415), ceUulose (416), or polymer blends (417,418) with a flame-retardant finish. 

Because we wanted to suppress the effects of thermodynamic quality of the eluent toward the polymer probes, we therefore looked for liquids that would be thermodynamically good solvents for PMMA. At the same time, one solvent should promote polymer adsorption whereas the others should promote desorption. 

In general, the adsorption of a surfactant on particles with previously adsorbed polymer can be influenced by (i) a reduction of surface area available for adsorption as a result of the presence of adsorbed polymer, (ii) possible interactions between polymer and surfactant in the bulk solution or in the interfacial region (that is, surfactant with loops, tails or trains of adsorbed polymer molecules), (iii) the steric effect of adsorbed polymer, preventing approach of surfactant molecules for adsorption at the surface, or (iv) possible electrostatic effects if polymer and/or surfactant are charged species. 

It is postulated that the main thermodynamic driving force for particle adsorption at the liquid-liquid interface is the osmotic repulsion between the colloidal particles and hydrophilic starch polymer molecules. This leads to an effective depletion flocculation of particles at the boundaries of the starch-rich regions. At the same time, the gelatin has a strong tendency to adsorb at the hydrophobic surface of the polystyrene particles, thereby conferring upon them some degree of thermodynamic... 

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