Membrane rheological properties

A different mechanism should account for the antioxidant ability of hydrophobic flavonoids, which can be incorporated into the bilayer where they can affect certain membrane physical properties. It is well-known that alterations in membrane rheology will affect the extension and rate of lipid oxidation. For example, increased lipid oxidation rates have been observed... 

Chronic diseases include cystic fibrosis in which nasal mucus is thick and viscous as a result of abnormal chloride transport across the membrane of the epithelial cells, leading to reduced water secretion. Similarly, chronic sinusitis also reduces nasal mucociliary clearance due to an increase in the rheological properties of mucus. 

Change in rheologic properties of biological membrane due to mucolytic action... 

Stevens et al. [86] proposed the replacement of the surfactant with fluids to modify the rheological properties and stabilize the emulsion. The aim was to slow the drainage of the film between the coalescing drops, thereby increasing the stability of the membrane. Their study on the removal of chromium with Alamine 336 showed that the emulsion stabihty could be controlled with the addition of smaU amounts of polymer to the organic phase and that demulsification could be achieved by heating the system. 

The main topics to be covered build upon our knowledge of the mechanical and rheological properties of membranes and their response to perturbations. In the remaining parts of this introductory section, some of these properties are briefly described to set the basis for a discussion of the behavior and response of membranes to external forces. The following sections consider in detail the morphological changes and poration electric fields can induce in vesicles made of membranes in different phases, and the effects of media environment and various molecular inclusions in the lipid bilayer, that is, the specific membrane composition. Finally, some application aspects of the work are discussed. 

The effect of NaOH concentration on the ion transport and rheological properties of the Nafion ion exchange membranes may be attributable to some variation in the ionic domain structure in the presence of NaOH. Therefore, it is extremely Important to understand the ionic domain structure under these conditions. The anomalous behavior of Na" " ion transport as a function of NaOH concentration is seen more frequently in bilayer Nafion membranes in which one layer is treated with diamine and also in perfluorinated carboxylic ion exchange membranes. Several mechanisms have been proposed to explain their ion transport results including water absorption, transport of hydroxide ion tunneling, ion pairing mechanisms, etc. (54-56). As the ion transport properties are beyond the scope of this review, no detailed discussion will be presented. 

Ismailova, V.N., "Stmcture Formation and Rheological Properties of Proteins and Surface-Active Polymers of Interfacial Adsorption Layers" in Progress in Surface and Membrane Science 13(1979)... 

These molecules are actually supposed to penetrate the interfacial film surrounding the water droplets and hereby to alter the rheological properties of the film material. From the low dosage levels used, i.e., 5-20 ppm, one can conclude that these molecules are extremely efficient as film modifiers. A critical and decisive step for the HMW demulsifiers to perform optimally is the time requirement for the diffusion to the interfacial membrane and for the reorientation movement inside the film until local equilibrium is attained. 

An interdisciplinary team of leading experts from around the world discuss recent concepts in the physics and chemistry of various well-studied interfaces of rigid and deformable particles in homo- and hetero-aggregate dispersed systems, including emulsions, dispersoids, foams, fluosols, polymer membranes, and biocolloids. The contributors clearly elucidate the hydrodynamic, electrodynamic, and thermodynamic instabilities that occur at interfaces, as well as the rheological properties of interfacial layers responsible for droplets, particles, and droplet-particle-film structures in finely dispersed systems. The book examines structure and dynamics from various angles, such as relativistic and non-relativistic theories, molecular orbital methods, and transient state theories. 

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