Colloids characterization

Surface active electrolytes produce charged micelles whose effective charge can be measured by electrophoretic mobility [117,156]. The net charge is lower than the degree of aggregation, however, since some of the counterions remain associated with the micelle, presumably as part of a Stem layer (see Section V-3) [157]. Combination of self-diffusion with electrophoretic mobility measurements indicates that a typical micelle of a univalent surfactant contains about 1(X) monomer units and carries a net charge of 50-70. Additional colloidal characterization techniques are applicable to micelles such as ultrafiltration [158]. 

Earlier we described complex colloids as those having particles of variable chemical composition. Most colloids of biological and environmental origin and some of industrial origin are complex. These colloids represent a severe challenge for colloid characterization methods. 

Colloid Characterization by Sedimentation Field-Flow Fractionation. I. Monodis-perse Populations, J. C. Giddings, G. Karaiskakis, K. D. Caldwell, and M. N. Myers, J. Colloid Interface Sci., 92, 66 (1983). 

Colloid characterization is not the classical application of Th-FFF. Nevertheless, Th-FFF was first applied to silica particles suspended in toluene testing a correlation between thermal diffusion and thermal conductivity [397]. Although a weak retention was achieved, no further studies were carried out until the work of Liu and Giddings [398] who fractionated polystyrene latex beads ranging from 90 to 430 nm in acetonitrile applying a low AT of only 17 K. More recently, polystyrene and polybutadiene latexes with particle sizes between 50 pm and 10 pm were also fractionated in aqueous suspensions despite the weak thermal diffusion [215] (see Fig. 30). Th-FFF is also sensitive to the surface composition of colloids (see the work on block copolymer micelles), recent effort in this area has been devoted to analyzing surfaces of colloidal particles [399,400]. 

Colloid characterization by El-FFF has been attempted. First trials of the separation of polystyrene latexes were not successful as the samples were strongly adsorbed when an electrical field was applied, while the fraction of adsorbed particles increased at greater field intensity [36]. With the improved El-FFF channel working with lower electrical fields, uncoated and protein-coated poly-... 

Kammer, F.v. and Forstner, U., Natural colloid characterization using flow-field-flow-fractionation followed by multi-detector analysis, Water Sci. and Technol., 37, 173, 1998. 

Other factors also affect the stability of eolloidal solutions, in particular the pH of the environment. The surface molecules of the nucleus of the micelles of different colloidal systems can have acid, basic, or amphoteric properties. Colloids characterized by this feature are called, respectively, acidosid, basoids, and ampholitoids (Marchenko, 1965). It has been established that the coagulation threshold of acidoids (sols of weak acids) increases and that of basoids decreases when the pH is increased. 

H. van Olphen, An Introduction to Clay Colloid Chemistry, for Clay Technologists, Geologists and Soil Scientists, 2nd ed., Wiley (1977). (Explains how colloid characterization and stability can be applied to clay minerals.)... 

ViUholth K. G. (1999) Colloid characterization and colloidal phase partitioning of polycyclic aromatic hydrocarbons in two creosote-contaminated aquifers in Denmark. Environ. Sci. Technol. 33, 691—699. 

Vereda, R, dc Vicente, J., and Hidalgo-Alvarez, R., Colloidal characterization of micron-sized rod-Uke magnetite particles. Colloids Surf. A, 319, 122, 2008. 

Whitman, P.K. and Feke, D.L., Colloidal characterization of ultrafine sihcon carbide and silicon nitride powders, Adv. Ceram. Mater, 1, 366, 1986. 

The main objective of this chapter is to report on the preparation and characterization of thermally sensitive particles, and the pertinent aspects that should be considered before their utilization as a polymer support in the biomedical field. This is followed by an examination of the preparation of such hydrophilic thermally sensitive latex particles bearing reactive groups. Subsequently, the colloidal characterizations that are to be taken into consideration are presented. Finally, the chapter concludes by presenting and illustrating recent applications of thermally sensitive polymer colloids as solid supports in the biomedical field. 

All the methods used for colloidal characterization of crude oil can be classified as direct and indirect methods. 

Investigations of water-in-oil polymerizations employing new monomers or emulsifiers for which kinetic or colloidal characterization is incomplete, require careful nomenclature designation. Under such circumstances a general description such as Water-in-Oil Polymerization or Heterophase Polymerization is recommended until the physical and chemical nature of the polymerizations can be identified. The designations inverse-suspension, inverse-emulsion and inverse-microemulsion should be reserved for processes for which a relatively advanced level of understanding exists. 

Acryuc and styrene-Acryuc Polymers 18.4.2 Particle and colloidal characterization and stabilit r... 

Giddings, J.C. Karaiskakis, G. Caldwell, K.D. Myers, MJ4. Colloid characterization by sedimentation field-flow fractionation I. Monodisperse populations. J. Colloid Interf. Sci. 1983, 92 (1), 66. 

Hansen, M.E. Giddings, J.C. Beckett, R. Colloid characterization by sedimentation field-flow fractionation VI. Perturbations due to overloading and electrostatic repulsion. J. CoUoid. Interf. Sci. 1989,132 (2), 300. 

Colloidal characterization has been done by Pen Kern 7000 acoustophoretic technique which not only determines the charge on the particles but also assesses the role of impurities and their extent on the powder surface. 

Although much remains to be learned about the chemistry of the catalyst particles in this important application, in light of the advandng state of the art in metal colloid characterization (see Section 6.3) there is good reason to expect... 

Hsiao MH, et al. A temperature-induced and shear-reversible assembly of latanoprost-loaded amphiphilic chitosan colloids characterization and in vivo glaucoma treatment. Acta Biomater 2014 10(7) 3188—96. 

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