Micelle formation theoretical aspects

The hydrophobic interactions are known to control many aspects of self-assembly and stability of macromolecular and snpramolecular structures. This has obviously been useful in both theoretical analysis and technical development of chemical structures. Furthermore, the interaction between nonpolar parts of amphiphiles and water is an important factor in many physicochemical processes, such as surfactant micelle formation and adsorption or protein stability. To make the discussion short, this interaction will be discussed in terms of the measured data of the surface and interfacial tension of homologous series. Analyses have shown that there is no clear correlation therefore, different homologous series will be discussed separately. 

The self-assembly mechanisms of copolymers into nanostructures and their applications have been extensively reviewed elsewhere. The basis of the various aspects of this research area is the correlation of the polymer structures to the type and the structural parameters of the formed nanostructures, which are the keys for researchers to design needed nanostructures for applications such as drug delivery. Along this line, this chapter focuses on the principles of formation, theoretical structural-parameters predications, and the basic experimental aspects in preparation and characterization, as well as recent progress and applications of polymer micelles and vesicles. 

Hamley [7], Alexandridis and Lindman [8], Riess and co-workers [1,9], Goby [2], Quemener et al. [10] and Eisenberg et al. [3], to name but a few. In tbe following, we intend to present a brief overview on tbe main aspects of micelle formation and morphology, the experimental methods used for their characterisation, as well as theoretical and computer simulation predictions of their structural parameters. Furthermore, representative examples of the main classes of different amphiphilic copolymer-selective solvent systems will be presented, along with possible applications of such systems. 

The chapter is organized as follows. Section II briefly recalls the theoretical aspects of micellar dynamics and the expressions of the relaxation times characterizing the main relaxation processes (surfactant exchange, micelle formation/breakdown). Section III reviews studies of micellar kinetics of various types of surfactants conventional surfactants with a hydrocarbon chain, surfactants with a fluorinated chain, and gemini (dimeric) surfactants. Section IV deals with mixed micellar solutions. Section V considers the d5mamics of solubilized systems. Section VI reviews the dynamics of sur-... 

This class of association colloids can be further divided into several subgroups, which include micelles, vesicles, microemulsions, and bilayer membranes. Each subgroup of association colloids plays an important role in many aspects of colloid and surface science, both as theoretical probes that help us to understand the basic principles of molecular interactions, and in many practical applications of those principles, including biological systems, medicine, detergency, crude-oil recovery, foods, pharmaceuticals, and cosmetics. Before undertaking a discussion of the various types of association colloids, it is important to understand the energetic and structural factors that lead to their formation. 

The experimental-theoretical study of mesophase formation in amphiphilic systems emphasizes the basic chemical, physical, and materials science aspects of the systems. The most commonly discussed mesophases, beyond the simple micelles discussed in Chapter 4, are lamellar aggregated micellar (packed in various cubic and hexagonal close-packed arrays), columnar or ribbon phases (rod-shaped micelles stacked in a two-dimensional hexagonal or rectangular array) microemulsions, and the cubic bicontinuous mesophases. The experimental techniques normally used to identify these mesophases are NMR Uneshape analysis, diffusion measurements, smaU-angle neutron and X-ray scattering, and optical texture analyses. In addition, reconstraction of electron density profiles and very low temperature transmission electron microscopy (TEM) have been used to elucidate the details of these mesostractures. 

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