Reversible changes, interface properties

Electrorheological (ER) fluids are materials whose rheological properties (viscosity, yield stress, shear modulus, etc.) can be readily controlled using an external electric field. For example, in some cases, they can switch from a liquid-like material to a solid-like material within a millisecond with the aid of an electric field, by means of the so-called ER effect.1617 The unique feature of the ER effect is that ER fluids can reversibly and continuously change from a liquid state to a solid state. ER fluid research is focused mainly on the automotive and robotics industry as electrical and mechanical interfaces for applications such as clutches, brakes, damping devices, fuel injection, and hydraulic valves. However, more recently, there is growing... 

The availability of reversible redox couples. Many important interfacial events involve electron transfer or net redox changes. 2) A broadly based synthetic chemistry with which to make variations. 3) A synthetic basis for creating the interface. 4) High chemical stability in more than one oxidation state. 5) Potentially exploitable excited state or catalytic properties. 6)... 

It was noted that activity and conformation change with the amount of water inside micelles, pointing out the importance of the aqueous environment, easily adjustable as a function of the water content, which is impossible when studies are performed in aqueous solutions. Furthermore, because many properties (9) of the water core resemble those of water present at interfaces in biological systems, reversed micelles provide an excellent system for studying the interactions between polypeptides and interfacial water (10-11) or more generally their conformation when solubilized in micelles (12-15), depending on where the biopolymer is located inside the micelle and what its conformation is. 

As is well known, the bilayer structure of cell manbranes exhibits hydrophobic properties in the hydrocarbon part. This means that those molecules that must interact with the membrane interior must be hydrophobic. Anesthesia is brought about by the interaction between some suitable molecule and the lipid molecules in the biological membrane at the cell interface. The effect of pressure has been reported to be due to the volume change of membranes, which reverses the anesthesia effect. Local anesthetics are basically amphiphile molecules of tertiary amines, and some have colloidal properties in aqueous solution. The anesthetic power is determined by the hydrophobic part of the molecule. Surface tension measurements showed a correlation with the anesthetic power for a variety of molecules dibucane < tetracainebupivacainemepivacaine < lidocaine < procaine (aU as HCl salts). ... 

Microemnlsions with high surfactant concentrations provide a wide-range variation in the component ratio, which can result in essential changes in their structural behaviour and properties, in rearrangements of the interface, and in phase inversions. As a result, transitions become possible between three different phases (i) reverse microemnlsions (water/ oil w/o) composed of water microdroplets dispersed in a continuous oil phase and stabilized by the surfactant monolayer including a co-surfactant if necessary (ii) bicontinu-ous systans with both water and oil as continuous phases and surfactant molecules intertwined in a three-dimensional network (iii) direct microemnlsions (oil/water o/w) composed of the oil microdroplets dispersed in a continuous aqueous phase. ... 

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