Introduction the role of aqueous mixtures in chemistry and biology

1 Introduction the role of aqueous mixtures in chemistry and biology 

Examples of important amphiphilic binary mixtures inelude water and dimethyl sulfoxide (DMSO), water-methanol, water-ethanol, water-tertiary butyl aleohol (TEA), water and glycerol, water and dioxane, to name a few. These amphiphilic 

As these cosolvents contain both hydrophilic and hydrophobic groups, the same molecule can induce opposite effects in water. The hydrophilic part can interact with water to form strong HBs, while the hydrophobic part may induce cooperative ordering in the system by a hydrophobic hydration effect. These two effects combine together to regulate the extensive HB network of water in their aqueous binary mixtures that is reflected in strong, often anomalous non-ideal behavior in many physical properties such as viscosity, density, dielectric constant, excess mixing volume, surface tension, heat of formation, etc. 

Moreover, as the composition can be varied easily, a range of properties can be accessed or tuned by varying the composition. For example, we can control the dielectric constant of the solvent and the solubility of the solute, among other 

Despite their importanee, a satisfaetory microscopic understanding of such exotic properties is not available even now beeause of the complexity in the nature of their interactions. We have seen in the last two ehapters that description of either hydro-phobic or hydrophilic effects itself is quite difficult. Not surprisingly therefore the development of a theory of amphiphUie binaiy mixtures has been left for posterity. 

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