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Micelle, hairy

It is quite evident that both micellar structures can be obtained by the same amphiphilic diblock copolymer system only by changing the structural parameters of the AB copolymer. The relative lengths of the two blocks and the total of the copolymer not only dictate the morphology of the resulting micelles ( hairy vs. crew-cut ) but also determine the rest of the micellar characteristics (Aagg,... [Pg.33]

Fig. 6. Possible structures of block copolymer micelles. Top Hairy micelle Bottom Crew-cut micelle... Fig. 6. Possible structures of block copolymer micelles. Top Hairy micelle Bottom Crew-cut micelle...
In scaling theories, Rc, Rm> and Z are directly correlated to NA and Mb for the investigated micelles. Two limiting cases have to be distinguished, the starlike or hairy micelles with N < Nb and the crew-cut micelles with Na > Nb (Sect. 2.3). [Pg.111]

Daoud and Cotton have developed a scaling model for hairy micelles and have found that the micelle total radius, Rm, scales as N 5Zl/s [207]. Since Z <5,Rm <25<5. [Pg.111]

Van der Waals forces There has been some success in relating these forces to micellar stability. However, the steric stabilization has been found to be also of some importance. Especially, the hairy layer interferes with the interparticle approach. There are several factors that will affect the stability of the casein micelle system ... [Pg.207]

Holt, C., Horne, D.S. (1996). The hairy casein micelle evolution of the concepts and its implication for dairy technology. Netherlands Milk and Dairy Journal, 50, 85-111. [Pg.224]

Historically, ideas of casein micelle structure and stability have evolved in tandem. In the earlier literature, discussions of micellar stability drew on the classical ideas of the stability of hydrophobic colloids. More recently, the hairy micelle model has focused attention more on the hydrophilic nature of the micelle and steric stabilization mechanisms. According to the hairy micelle model, the C-terminal macropeptides of some of the K-casein project from the surface of the micelle to form a hydrophilic and negatively charged diffuse outer layer, which causes the micelles to repel one another on close approach. Aggregation of micelles can only occur when the hairs are removed enzymatically, e.g., by chymosin (EC 3.4.23.4) in the renneting of milk, or when the micelle structure is so disrupted that the hairy layer is destroyed, e.g., by heating or acidification, or when the dispersion medium becomes a poor solvent for the hairs, e.g., by addition of ethanol. [Pg.65]

Thus, the NMR spectra support the contention that the hairy layer of micelles is formed predominantly from the C-terminal peptide of a proportion (possibly as much as half) of the K-casein molecules. However, the mobile fraction will include contributions from any caseins that have dissociated from the micelles as a result of suspension in the 2H20 buffers and any mobile side chains inside the micelle, as well as the mobile external surface fraction. [Pg.123]

FIGURE 7.2 Calcium phosphate nanocluster model of a casein micelle. Substructure arises from the calcium phosphate nanocluster-like particles in the micelles (dark spheres). There is a smooth transition from the core to the diffuse outer hairy layer that confers steric stability on the micelle. (Courtesy of Holt and Roginski, 2001.)... [Pg.140]

Keywords Colloidal dispersions Colloidal glasses Dynamics Grafted particles Hairy particles Micelles Nanoparticle-polymer hybrids Phase diagrams Polymers Rheology Soft colloids- Softness Stars... [Pg.5]

The ultrasonification process is connected with the rapidly increased oil-water interfacial area as well as the significant re-organization of the droplet clusters or droplet surface layer. This may lead to the formation of additional water-oil interface (inverse micelles) and, thereby, decrease the amount of free emulsifier in the reaction medium. This is supposed to be more pronounced in the systems with non-ionic emulsifier. Furthermore, the high-oil solubility of non-ionic emulsifier and the continuous release of non-micellar emulsifier during polymerization influence the particle nucleation and polymerization kinetics by a complex way. For example, the hairy particles stabilized by non-ionic emulsifier (electrosteric or steric stabilization) enhance the barrier for entering radicals and differ from the polymer particles stabilized by ionic emulsifier. The hydro-phobic non-ionic emulsifier (at high temperature) can act as hydrophobe. [Pg.162]

K-casein on the other (31). Moreover, these simple systems show appreciable differences from native casein micelles in their response to Ca ". In casein micelles, the binding sites for Ca appear to be some distance from the surface of the hairy layer (13) and the same argument can be presumably used for the individual caseins, and show that the calcium binding sites in the synthetic particles are within the surface of shear. On the other hand, the binding of Ca may cause conformational changes in the interfacial layer. [Pg.672]

Gel-like structure is another model that states casein molecules are located in micelle in a tangle manner and comphcated situation, forming a sphere. In addition, /c-caseins stretch out of the micelle and form a hairy layer. In this model, which was proposed by Holt [35], calcium phosphate nanoclusters act as linkers of thread-like casein monomers by cross-linking [2, 29, 36, 37]. In this model the calcium phosphate nanoclusters are responsible for linking the caseins molecules to each other whereas in previous proposed model nanoclusters are the joiners for submicelles. [Pg.173]


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See also in sourсe #XX -- [ Pg.190 ]




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