Partitioning phases

The cleaning process proceeds by one of three primary mechanisms solubilization, emulsification, and roll-up [229]. In solubilization the oily phase partitions into surfactant micelles that desorb from the solid surface and diffuse into the bulk. As mentioned above, there is a body of theoretical work on solubilization [146, 147] and numerous experimental studies by a variety of spectroscopic techniques [143-145,230]. Emulsification involves the formation and removal of an emulsion at the oil-water interface the removal step may involve hydrodynamic as well as surface chemical forces. Emulsion formation is covered in Chapter XIV. In roll-up the surfactant reduces the contact angle of the liquid soil or the surface free energy of a solid particle aiding its detachment and subsequent removal by hydrodynamic forces. Adam and Stevenson s beautiful photographs illustrate roll-up of lanoline on wood fibers [231]. In order to achieve roll-up, one requires the surface free energies for soil detachment illustrated in Fig. XIII-14 to obey... 

Other properties that are influenced by H bonding are solubility and miscibility, heats of mixing, phase-partitioning properties, the... 

Another parameter used to characterise two-phase partitioning is the purification factor, defined as ... 

Mondal, K. Sharma, A. and Gupta, M. N. (2004). Three phase partitioning of starch and its structural consequences. Carbohydrate polymers, 56, 355-359. 

The gas phase partition function Qg s of the atom is the same however, since the atoms are immediately immobilized on a two-dimensional surface, we need to take the configuration of the adsorbed atoms into account in the transition state. Again we consider a surface containing M sites each with an area of a. The density of sites per area is Nq = M/A = 1 /a. The M sites are not necessarily free as some could be occupied already hence, the number of free sites will be M and 0 = M /M = (1-0a)-If we have N atoms adsorbed on these sites (we again use for the transition state Airmobile), the partition function for this system is given by... 

Relative hydrophobicity and lipophilicity of P-blockers and related compounds as measured by aqueous two-phase partitioning, octanol-buffer partitioning, and HPLG. Eur. J. Pharm. Sci. 2002, 17, 81-93. 

On the subject of applications of such experimental parameters, the questions of whether an ionized molecule may or may not partition into octanol and whether bulk-phase partitioning is in turn adequate to describe bilayer partitioning are important and pertinent ones, and are addressed in Section 16.3. 

Seventy years later, this theory largely holds true, although periodically challenged [67, 68]. Observation of transmembrane permeability of ionic species was initially explained by the formation of neutral ion-pair [69, 70]. A comprehensive review of the physicochemical properties influencing permeation has been written by Malkia et al. [5]. The reality is that, despite many studies, the effect of ionization on permeation is still a matter of discussion and active research. In contrast, it became clear that bulk-phase partitioning measurements are not adequate to describe bilayer partitioning [71-73]. 

Hurley JP, Cowell SE, Shafer MM, Hughes PE. 1998. Tributary loading of mercury to Lake Michigan importance of seasonal events and phase partitioning. Sci Total Environ 213 129-137. 

Precipitation is a phase-partitioning process whereby solids separate from a solution.34 Dissolution involves movement from the solid or gaseous phase to the aqueous phase. Solids dissolve into ions, whereas gases retain their original chemical structure when dissolved. The solubility of a compound (its tendency to dissolve in water or other solutions) is the main property affecting the precipitation-dissolution process. 

Koukounis, C., Wade, U.H., and Schechter, R.S. "Phase Partitioning of Anionic and Nonionic Surfactant Matures," SPE paper 8261, 1979 SPE Annual Fall Technical Conference and Exhibition of AIME, Las Vegas, September 23 26. 

Directed movement energy Interaction between phases (partition, adsorption) ... 

Malinowski, J.J. (2001) Two-phase partitioning bioreactors in fermentation technology. Biotechnology Advances, 19, 525-538. 

Tjerneld, F. (1992) Aqueous two-phase partitioning on an industrial scale. In Poly (Ethylene Glycol) Chemistry Biotechnical and Biomedical Applications (J.M. Harris, ed.), pp. 85-102. Plenum, New York. 

Thoms, S.R., Lion, L.W. (1992) Vapor-phase partitioning of volatile organic compounds a regression approach. Environ. Toxicol. Chem. 11, 1377-1388. 

Eadie, B.J., Morehead, N.R., Landrum, P.F. (1990) Three-phase partitioning of hydrophobic organic compounds in Great Lakes waters. Chemosphere 20, 161-178. 

Santesson, S. Ramirez, I. B. R. Viberg, P. Jergil, B. Nilsson, S., Affinity two phase partitioning in acoustically levitated drops, Anal. Chem. 2004, 76, 303 308... 

All chromatographic methods function on the same principle, which is the partitioning of components in a mixture between two phases (1) a stationary phase, which may be a solid, liquid, or gel, and (2) a mobile phase, which may be gas, liquid, solution, or a varying mixture of solvents. When a mixture is introduced into a chromatographic system, its components are alternately absorbed and desorbed, that is, partitioned between, the stationary and mobile phases. Partitioning is caused by different polarities of the stationary and mobile phases and the compounds being separated. Compounds in the mixture have different affinities for the phases and they will move at different rates in the chromatographic system and thus be separated. 

Mobile phase Partition Thin layer Ion exchange Electrophoresis... 

The complexing ability of crown ethers in solvents of low polarity has been studied using two-phase partition experiments (Frensdorf, 1971b). The equilibrium between an aqueous solution of the salt (MX) and an organic solution containing the crown ether (Cr) is given by (2). Further dissociation of... 

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