Aggregates micelles vesicles

An outline of the ideas is as follows [62-65]. It suffices to assert that a dilute solution of surfactant molecules can be considered to consist of water plus monomers, dimers, trimers, and larger allowed aggregates (micelles, vesicles, liposomes,. ..). The concentration is assumed to be so low that aggregates can be considered to be non-interacting. The probability distribution of aggregates, is then determined from the law of mass action... 

L. Garcfa-Rfo, P. Herves, J.C. Mejuto, J. Perez-Juste, and P. Rodrfgnez-Dafonte, Comparative stndy of nitroso group transfer in colloidal aggregates Micelles, vesicles and microemnlsions, 2003, New J. Chem. 27, 372-380 and references therein. 

We have already seen in Chapter 5, on self-organization, how and why amphiphilic molecules tend to form aggregates such as micelles, vesicles, and other organized structures. 

Macrocyclic host molecules, medium-sized aggregates (microemulsions, micelles,vesicles, etc.) and mesoporous materials as catalysts... 

Molecular aggregates. Micelles, microemulsions, vesicles, liquid crystals, dendromers, monolayers, Langmuir-Blodgett (L-B) films, and so forth have dimensions of tens of angstroms or larger, and the photochemistry in this class of microreactor has been extensively investigated. 

Another of the most fascinating properties of block copolymers is their ability to self-assemble into micelles, aggregates, and vesicles of various morphologies in the presence of a selective solvent, [117,118] and recent studies have demonstrated that self- assemble of amphiphilic block copolymers into various morphologies occurs not only in selective solvents but also at interfaces and surfaces [119,120],... 

Keywords Block copolymers ABC triblock copolymers Janus micelles Cylinder brushes Core-shell nanoparticles Graft copolymers Micelles Vesicles Copolyampholytes Polyelectrolyte block copolymers Aggregation... 

The following Sect. 2 deals with the association of diblock copolymers and discusses micelles, vesicles, micellar aggregation and interaction. In Sect. 3 recent work on micelle and vesicle formation of triblock copolymers is presented, whereas in Sect. 4 more complicated architectures such as graft copolymers, cylindrical brushes and Janus micelles are discussed. 

Few studies exist for ionic silicone surfactants. Several trisiloxane anionic, cationic and zwitterionic surfactants have been found to form micelles, vesicles and lamellar liquid crystals. As would be expected, salt shifts the aggregates toward smaller curvature structures [40]. 

We begin here a brief survey of thermodynamic principles that pertain to formation and self assembly of large scale aggregates of molecular units, such as polymers, micelles, vesicles, or similar macromolecules. We follow the exposition of Israelachvily. ... 

It is noteworthy and interesting that both the tensiometry and the fluorescence measurements give an order of CAC values for the series of copolymers with 4, 6 and 10 DMS units that is opposite to the expected order. The usual trend for surfactants is that the aggregation, which is usually micelle formation, starts at lower concentration the longer the hydrophobic tail. With the dimethylsiloxane sur ctants studied in this work, the trend is the opposite. We believe the reason for this is that we observe the formation of vesicles instead of micelles. (Vesicles are dispersions of a lamellar phase in water.)... 

Note that the observed behavior supports the assumption that the substrate in one aggregate unit (micelle, vesicle) does not react with the reactant in another this is further evidence of effective compartmentalization in aggregates. 

It should be noted that LLC phases are different from the ubiquitous individual, phase-separated aggregate structures commonly formed by amphiphilic molecules or surfactants, such as micelles, reverse micelles, vesicles, and lipid microtubules. These discrete aggregate structures formed from amphiphiles lack periodic order, and are not condensed-phase materials—two defining characteristics of LLC phases. For the purposes of this review, LLC phases will he defined as fluid, condensed-phase materials composed of amphiphilic molecules that have periodic order and are formed via phase separation of the amphiphiles around an added solvent as a secondary component (i.e., mixtures). Consequently, functional normal micelle, reverse micelle,... 

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