Surface-active medium stress concentrators

Finally, it is worth emphasizing the role of the stressed state. The combined action of the medium and mechanical stresses forms a common group of the adsorption effects considered. One characteristic feature of this group is the influence of stressed states in which the predominant role is played by the extension component. If the stresses are of a compressive nature (especially within surface layers), the influence of the active medium may not necessarily be revealed. Consequently, various stress concentrators, such as recesses or threads, may have an especially negative impact on strength and durability. 

The situation becomes most complicated in multicomponent systems, for example, if we speak about filling of plasticized polymers and solutions. The viscosity of a dispersion medium may vary here due to different reasons, namely a change in the nature of the solvent, concentration of the solution, molecular weight of the polymer. Naturally, here the interaction between the liquid and the filler changes, for one, a distinct adsorption layer, which modifies the surface and hence the activity (net-formation ability) of the filler, arises. Therefore in such multicomponent systems in the general case we can hardly expect universal values of yield stress, depending only on the concentration of the filler. Experimental data also confirm this conclusion [13],... 

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