CMC is not exactly an instantaneous “black-white” transition from a 100% random solution to a 100% micellar solution (where the micelle concentration is 100%) upon increasing copolymer levels or upon dilution (Loh 802). The figures do, however, change even if not by exactly 100%. Analysis of the block copolymer molecular structure results and the critical micelle concentration weight was undertaken by the use of ionic liquids (Ruiz et al. 3229) that acted as main model solvents. The researchers used Pyrene Fluorescence (Bains et al. 6209) to measure CMCs as a block MW function for three polystyrene–poly (ethylene oxide) samples and three PS–poly (methyl methacrylate) samples in 1-ethyl-3methylimidazolium bis(trifluoromethylsulfonyl) amide (Jean and Ache 984). The findings were that the amount of CMC reduced by a shy value of 1.5 in the PSPEO, in which the solvophobic PS block MW was unchanged at (20 000) or 100% while the PEO block MW reduced considerably from 15 000 to 3000. These findings conformed accurately with those of the self-consistent-field (SCF) theory (Egorov 2). A higher decrease of about 5 was observed in the PMMA series. Here the solvophobic PS block MW was increased from 3000 to 11 000 while keeping a persistent overall MW (ca. 15 000). However, this reduction was much weaker than the one forecasted by SCF calculations.
Critical Micelle Temperature (CMT)
A similar scenario with regards to Critical Micelle Temperature (CMT) is as follows. Micellar conduct of cationic surfactants, dodecyldimethylethylammonium bromide (DDAB) and dodecyltrimethylammonium chloride (DTAC) in media that is aqueous has been researched in temperatures between 288.15–308.15 K (Evans et al. 4132). In defining the critical micelle concentration (CMC) and the ionization degree (β) of the micelles, research employs conductivity results at varying temperatures (Mata et al. 550). In determining the behavior of the DTAC and CMC (Miguel and Burrows 123), there was a comparison of DTAB results in terms of alkyl chain reaction. On the other hand, evaluation of thermodynamic in the micelle system is undertaken by use of pseudo-phase separation model (Biresaw and Mittal 390).
Solvent effects on the phenomena
Lipid micelles constitute a molecular assembly in that individual parts exist thermodynamically in equilibrium. The monomers of the same species are also in a nearby medium. In water or in a solvent, there is continuous interaction between hydrophilic “heads” of molecules and the solvent (water) (Nalwa 573). This happens despite the state of the surfactants that could either be as monomers or as micelles. Lipophilic substances, however, have fewer interactions with the solvent while being part of a micelle. This is the source for the micelle formation drive. In a micelle, the hydrophobic tails of various molecules gather into a grease-like basic which forms the most constant arrangement which has no contact with the solvent.
Exchange of single polymer change among micelles
The rate of change strongly depends on the length of an alkyl-chain and the relaxation function nearly seamlessly trails the single exponential decay forecasted by theory. Surface grafted polymers, for instance, poly (ethylene glycol) (PEG), act as a steric barrier in surface-surface macromolecule interactions. Studies previously undertaken indicate that in order to reveal a single lipid vesicle to a solution of MOPC, Micropipette manipulation is applied. The measurement of MOPC was done through a direct calculation of the vesicle area change. There are many studies that have been advanced to show the exchange of single polymer change among micelles. The ones discussed are just but a few. There are, however, many others that have been discussed in lengthy detail. The changes are numerous and the findings varying from one research to the other.
Works Cited
Bains, Gursharan K, Sea H Kim, Eric J Sorin and Vasanthy Narayanaswam. “The Extent of Pyrene Excimer Fluorescence Emission Is a Reflector of Distance and Flexibility: Analysis of the Segment Linking the LDL Receptor-Binding and Tetramerization Domains of Apolipoprotein E3.” Biochemistry 51.31(2012): 6207-6219. Print.
Biresaw, Girma and Kashmiri Lal Mittal. Surfactants in Tribolog, 2 vols. Florida: CRC Press, 2013. Print.
Egorov, S A. “Sterically stabilized lock and key colloids: A self-consistent field theory study.” Journal of Chemical Physics (2011): 1-6. Print.
Evans, Christopher M, Kevin J Henderson, Jonathan D Saathoff, Kenneth R Shull and John M Torkelson. “Simultaneous Determination of Critical Micelle Temperature and Micelle Core Glass Transition Temperature of Block Copolymer–Solvent Systems via Pyrene-Label Fluorescence.” Macromolecules 46.10(2013): 4131-4140. Print.
Jean, Yan-Ching and Hans J Ache. “Paper Determination of critical micelle concentrations in micellar and reversed micellar systems by positron annihilation techniques.” Journal of The American Chemical Society (1978): 984-985. Print.
Loh, Watson. Block Copolymer Micelles. 2002. Web.
Mata, P Jitendra, Majhi, P R; Guo, C; Liu, H Z and Bahadur, P. “Concentration, temperature, and salt-induced micellization of a triblock copolymer Pluronic L64 in aqueous media.” Journal of Colloid and Interface Science 292.2 (2005): 548-556. Print.
Miguel, Maria da Graca and Hugh D Burrows. Trends in Colloid and Interface Science XVI, Volume 123. Chennai: Springer, 2004. Print.
Nalwa, Hari Singh. Handbook of Surfaces and Interfaces of Materials, Five-Volume Set. Califonia: Academic Press, 2001. Print.
Ruiz, Cristóbal Carnero, José Antonio Molina-Bolívar, José Manuel Hierrezuelo and Esperanza Liger. “Self-Assembly, Surface Activity and Structure of n-Octyl-β-D-thioglucopyranoside in Ethylene Glycol-Water Mixtures”. International Journal of Molecular Science.s 14.2 (2013): 3228-3253.