Properties colloid-chemical

With respect to SCF models that focus on the tail properties only (typically densely packed layers of end-grafted chains), the molecularly realistic SCF model exemplified in this review needs many interaction parameters. These parameters are necessary to obtain colloid-chemically stable free-floating bilayers. A historical note of interest is that it was only after the first SCF results [92] showed that it was not necessary to graft the lipid tails to a plane, that MD simulations with head-and-tail properties were performed. In the early MD simulations (i.e. before 1983) the chains were grafted (by a spring) to a plane it was believed that without the grafting constraints the molecules would diffuse away and the membrane would disintegrate. Of course, the MD simulations that include the full head-and-tails problem feature many more interactions than the early ones. 

Particles in the nanometer-size regime necessarily have large surface-to-volume ratios approximately one-third of the atoms are located on the surfaces of 40 A CdS particles, for example. Furthermore, colloid chemical preparations typically result in the development of surface imperfections and in the incorporation of adventitious or deliberately added dopants. Such surface defects act as electron and/or hole traps and, thus, substantially modify the optical and electro-optical properties of nanosized semiconductor particles. Altered photostabilities [595], fluorescence [579, 594, 596, 597], and non-linear optical properties [11, 598-600] are manifestations of the surface effects in colloidal semiconductors. 

A colloid chemical approach to CdS/HgS/CdS spherical quantum wells was described [79]. Size-dependent third-order non-linear susceptibilities of CdS clusters were investigated [80]. Reviews appeared on size-quantized nanocrystalline semiconductor films [81] and on the quantum size effects and electronic properties of semiconductor microcrystallites [82]. 

Morgan, J. J., and Stumm, W. (1964). Colloid-chemical properties of manganese dioxide. J. Colloid Sci. 19, 347-359. 

The special properties of thin liquid films, in particular of foam films, involve studying various colloid-chemical aspects, such as kinetics of thinning and rupture of films, transition from CBF to NBF, isotherms of disjoining pressure, thermodynamic (equilibrium) properties, determination of the electrical parameters of surfactant adsorption layer at the liquid/gas... 

The cation exchange of layer silicates significantly influences some structural and colloid chemical properties. Depending on the charge of the cation, the interlayer space contains water in different quantities (Chapter 2, Section 2.1.2). So, the basal spacing (the distance between similar faces of adjacent layers) is different for monovalent, bivalent, and trivalent cations. For example, in monovalent montmorillonite, it is about 1.2 nm, and in bivalent and trivalent montmorillonite, it is about 1.5—1.6 nm. 

The various bentonite samples have different physical, chemical, and colloid chemical properties. The particle size distribution, specific surface area, CEC, and swelling in water are shown in Table 3.2. For an easier comparison, some... 

S. J. Park and Y. S. Jang, Pore structure and surface properties of chemically modified activated carbons for adsorption mechanism and rate of Cr(VI), J. Colloid Interface Sc/. 249 (2002) 458-463. 

Ocourrenoe — History — Treatment of Uranium Minerals — Preparation of Uranium—Ph37sioal Properties—Spectrum—Chemical Properties—Pyrophoric Uranium—Colloidal Uranium— Atomic Weight—Isotope.s of Uranium—Alloys. 

Scholtan, W., Sy, L. Kolloid-chemische Eigenschaften eines neuen Kurznarkotikums. Teilgewicht der Mizelle und Verteilungsgleichgewicht des Wirkstoffes. (Colloidal chemical properties of a new short-acting anesthetic. Particle weight of the micelle and distribution equilibrium of the active compound.). Arzneimit.-Forsch. 1966,16, 679-691. 

Kleijn, J.M., and Lyklema, J., Colloid-chemical properties of ruthenium dioxide in relation to catalysis of the photochemical generation of hydrogen, Colloid Polym. Sc/., 265, 1105. 1987. 

It is noteworthy that many proteins in the monolayer state retain their enzymatic activity and are capable of taking part in specific chemical reactions. For this reason the colloid-chemical methods used to investigate the properties of protein films, combined with other techniques, represent valuable tools for the study of the properties of proteins. These methods allow one to examine more closely mechanisms of transport phenomena that take place at cellar interfaces in biological systems. The latter are the interfaces at which the accumulation of surface active substances with biological and physiological activity occur. These substances, when present at such interfaces, reveal their important unique properties (e.q. enzymatic activity). 

Among the studies of colloid-chemical properties of polymer solutions one may outline three directions that have been under the most intense development in recent decades. 

Answers to these questions have been developed slowly in comparison to rapid advances in our knowledge of air particulates based on studies completed in the late 1960 s. This is partly a result of superior sampling devices for size and chemical characterization of air particulates, and partly a result of the more heterogeneous nature of water particulates. The size spectrum of particulates in water extends from colloidal humic substances 1 nm in size, to large aggregates such as fecal pellets or marine snow with sizes up to 10" m. The distribution of shapes, densities, surface chemical properties, and chemical composition may vary widely with size. Some fractions of the size spectrum may be living, and all particulates are subject to diverse physical-chemical and biological processes that can alter size distributions, shape, or chemical composition. 

Protein adsorption on solid surfaces is discussed from a colloid chemical and thermodynamic point of view. Information is mainly obtained from adsorption isotherms, (proton)titrations, electrokinetics and calorimetry. The adsorption behavior of human plasma albumin and bovine pancreas ribonuclease at various surfaces is studied. The differences in behavior between the two proteins are related to differences in the structural properties. Furthermore, the essential role of the low molecular weight electrolytes in the overall protein adsorption process is stressed. 

The heat treatment has a remarkable effect on the colloid chemical properties of PVA fibers. The fibers treated at 145°C showed a shrinkage of about 50% in water at 45°C. As the temperature of the heat treatment was increased, shrinkage decreased rapidly and became less... 

Kim, E.H.J. Chen, X.D. Pearce, D. Surface characterization of four industrial spraydried dairy powders in relation to chemical composition, structure and wetting property. Colloids and Surfaces, B Biointerfaces, 2002,26(3), 197-212. 

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