Permeability polymer adsorption affected

With a three-component system, such as a polymer in an aqueous salt solution, preferential adsorption of one component to the polymer can affect the analysis of light-scattering data.199 Such interactions can affect the SRI. Therefore, measurements of the SRI must be made at constant chemical potential. Constant chemical potential is achieved experimentally by dialyzing the solvent and polymer solution to equilibrium through a membrane permeable to the solvent but impermeable to the polymer.199... 

In a practical polymer flood calculation in a real reservoir, there will be several rock types. Not only will the permeability vary over quite a large range, but the actual details of the reservoir lithology may also differ in different regions of the reservoir. For example, there may be certain geological strata that have a higher active clay content than other strata, and this affects the polymer adsorption/retention behaviour. Permeability itself is also... 

Although the permeability reduction, which is defined as the ratio of flow rates before and after adsorption, was strongly affected by the nature of porous media, its dependence on the shear rate was similar for both polymers. A clear and reversible change of LH... 

Moisture is also an important factor that can affect the stability of candidate drugs and their formulations. Sorption of water molecules onto a candidate drug (or excipient) can often induce hydrolysis (see, e.g., Yoshioka and Cartensen 1990). In this situation, by sorbing onto the drug-excipient mixture, the water molecules may ionize either or both of them and induce a reaction. For example, we have found that a primary amine, when mixed with lactose, was apparently stable even when stored at 90°C for 12 weeks. However, when the experiment was carried out in the presence of moisture, extensive degradation by way of the well-known Mailliard reaction took place. Other properties such as crystal structure, powder flow, compaction, lubricity, dissolution rate and polymer film permeability may also be affected by moisture adsorption (Ahlneck and Zografi 1990). 

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