Micelle growth

Fig. 4. MiceUular gelation mechanism. A shows micelle nuclei, highly cross-linked B, boundary where micelle growth terminates in styrene block polymers.

These results suggest that interactions between silicate species and surfactant micelles are weak in the precursor solution. The absence of any organization in the system prior to precipitation seems to indicate that the most important step in the process is the formation of siliceous prepolymers. The interaction of these prepolymers with surfactants could be responsible for micelle growth and subsequent reorganization of the silica/micelle complexes into ordered mesoporous structures. Such a hypothesis might be confirmed by preliminary potentiometric measurements using a bromide ion-specific electrode the amount of free bromide anion increasing at pH around 11 when the polymerization of silica starts. 

Fig. 4. Micellular gelation mechanism. A shows micelle nuclei, highly cross-linked B, boundary where micelle growth terminates in styrene block polymers. Styryl free radicals simultaneously initiate micelle nuclei at points of high fumarate concentration. The micelles continue to expand, interacting with free styrene until the fumarate groups are depleted. The micelles eventually overlap at the boundaries that contain higher levels of terminal styrene...

Fig. 3 The CARD model. Catalysed micelle growth and fission. L,- and Lj molecules are different amphiphilic compounds, kj and fc are rate constants for spontaneous insertion and emigration of amphiphile L , and fiij is the rate enhancement of getting in and out of this molecule from the micelle, catalysed by Lj. Note that the model does not deal with the primary origin of L molecules per se (from [23])...

In an attempt to design a protocell, a Los Alamos group proposed a system essentially composed of non-enzymatic template replication coupled to micelle growth [55,56]. The micelle aggregate is assumed to incorporate from the medium precursors of lipids and template building blocks (monomers or oligomers). The authors assume that for this particular construct PNAs [57] would serve better because of their hydrophobic nature. It is assumed that single-stranded molecules face the hydrophilic anterior whereas double-stranded molecules immerse into the hydrophobic interior of the micelles. Alternation between these two states is assumed to facilitate replication. 

Recently, Slattery and Evard (171) proposed a model for the formation and structure of casein micelles from studies devoted to association products of the purified caseins. They proposed that the micelle is composed of polymer subunits, each 20 nm in diameter. In the micellar subunits the nonpolar portion of each monomer is oriented radially inward, whereas the charged acidic peptides of the Ca2+-sensitive caseins and the hydrophilic carbohydrate-containing portion of K-casein are near the surface. Asymmetric distribution of K-casein in a micelle subunit results in hydrophilic and hydrophobic areas on the subunit surface. In this situation, aggregation through hydrophobic interaction forms a porous micelle (Figure 10). Micelle growth is limited by the eventual concentration, at the micelle surface, of subunits rich in K-casein. 

Micelle growth is favored by an increase in f, as is critical wall shear stress for drag reduction [Rose and Foster, 1989 Chou, 1991 Lu, 1997 Lu et al., 1998b Lin et al., 2001]. However, at high values of f, some systems become insoluble [Qi, 2002]. The effect of I on TLM formation is complex, depending on both molecular structures... 

However, joining of K-casein to any of other caseins via its hydrophobic region leads to the termination of micelle growth because /c-casein just owns 1 hydrophobic segment and does not interact with CCP nanoclusters due to the lack of phosphoseiyl residues [2, 40]. This model is basically different in comparison with previous models in term of internal structure of micelles however, the cement role of CCP and location of K-casein on the surface of micelle are identical. 

Salt-free dilute solutions of 12-2-12, 2Br" (surfactant volume fraction below 1%) show shear-induced structuration (micelle growth) resulting in an increase of viscosity, as illustrated in Fig. 16 [118]. 

Having reviewed the properties of single adsorption monolayers, we proceed with the couples of interacting monolayers the thin liquid films. First, we present the thermodynamics of thin films, and then we describe the molecular theory of the surface forces acting in the thin films. We do not restrict ourselves to the conventional DLVO (Deijaguin, Landau, Verwey, Overbeek) forces [2,3], but consider also the variety of the more recently discovered non-DLVO surface forces [4]. The importance of the micelle-micelle interaction for the mechanism of micelle growth is also discussed. 

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