Surface chemical characteristics

Somasundaran, P. Wang, Y. H. C. 1984. Surface chemical characteristics and adsorption properties of apatite. In MlSRA, D. N. (ed) Adsorption and Surface Chemistry of Hydroxyapatite. Plenum Press, New York, 129-149. 

A detailed study of chlorhexidine s surface-chemical characteristics was undertaken in our laboratories. This included work with a series of carefully selected analogs comprising segments of the parent molecule (Structure II R = n-hexyl, n-propyl, or H) or extensions of these (Structure II R = n-octyl or n-dodecyl). 

Mathur, B.S. and Venkataramani, B., Surface charge and surface chemical characteristics of magnetites substituted with nickel, cobalt and chromium. Colloids Surf. A, 140, 403, 1998. 

In single-metal systems, the adsorption or coprecipitation of the metal ion [25] alters the surface chemical characteristics of the substrate. In multiple metal systems, then, the surface seen by a second or third adsorption metal ion is different from the original surface. This one might expect to see significant changes in the removal behavior. Furthermore, it the metal ions have similar hydrolytic behavior, they may interact in solution prior to, or in combination with, adsorption. Thus simple adsorption experiments may involve coprecipitation among the adsorbing metal ions, even if the substrate is added preformed. 

In this section, the literature pertaining to the relationship between the practical adhesion and surface-chemical characteristics — contact angle, solubility parameter etc. — of... 

The electron beam technique has often been utilized for surface modification and properly improvement of polymer materials like fibers, films, plastics, and composites in recent decades [104-107]. It may remove surface impurities and alter surface chemical characteristics at an appropriate irradiation condition. Electron beam processing is a dry, dean, and cold method with advantages such as energysaving, high throughput rate, uniform treatment, and envirorunental safety. 

The Pd/Sn catalyst is these studies was obtained from Shipley Co. It should be noted that Pd/Sn catalysts from other manufacturers may have different surface chemical characteristics, and results from these e q)eriments may not be generalizable to all Pd/Sn formulations. 

Traditional adsorbents such as sihca [7631 -86-9] Si02 activated alumina [1318-23-6] AI2O2 and activated carbon [7440-44-0], C, exhibit large surface areas and micropore volumes. The surface chemical properties of these adsorbents make them potentially useful for separations by molecular class. However, the micropore size distribution is fairly broad for these materials (45). This characteristic makes them unsuitable for use in separations in which steric hindrance can potentially be exploited (see Aluminum compounds, aluminum oxide (ALUMINA) Silicon compounds, synthetic inorganic silicates). 

The subsequent improvement of the physical and chemical characteristics of these membranes, their incorporation into machines, and the development of procedures to prevent or clean surface-fouling films were the principal areas of significant advancement. By 1990, the industrial ultrafiltration market had grown to an estimated (90-100) x 10 . ... 

The surface burning characteristics (flame spread index and smoke developed index) for wood and wood products as measured by American Society for Testing and Materials (44) can be reduced with fire retardant treatments, either chemical impregnation or coatings (48). Fire retardant treatments also reduce the heat release rate of a burning piece of wood (49,50). The heat release rates (51) of the burning materials are an important factor in fire growth. 

J) The extreme fineness of iadividual clay particles, which may be of colloidal size ia at least one dimension. Clay minerals are usually platy ia shape, and less often lathlike and tubular or scroU shaped (13). Because of this fineness clays exhibit the surface chemical properties of coUoids (qv) (14). Some clays possess relatively open crystal lattices and show internal surface colloidal effects. Other minerals and rock particles, which are not hydrous aluminosihcates but which also show colloidal dimensions and characteristics, may occur intimately intermixed with the clay minerals and play an essential role. 

Leachate in landfills. Leachate may be defined as hquid that has percolated through sohd waste and has extracted dissolved or suspended materials from it. In most landfills, the liqiiid portion of the leachate is composed of the liquid produced from the decomposition of the wastes and liquid that has entered the landfill from external sources, such as surface drainage, rainfall, groundwater, and water form underground springs. Representative data on chemical characteristics of leachate are reported in Table 25-72. 

The powders of zeolites of various trademarks are used to produce petroleum-refining catalysts. In this connection, it is very important to have complete information concerning not only chemical composition and distribution of impurity elements, but also shape, surface, stmcture and sizes of particles. It allows a more detailed analysis of the physical-chemical characteristics of catalysts, affecting their activity at different stages of technological process. One prospective for solving these tasks is X-ray microanalysis with an electron probe (EPMA). 

The vast majority of modem liquid chromatography systems involve the use of silica gel or a derivative of silica gel, such as a bonded phase, as a stationary phase. Thus, it would appear that most LC separations are carried out by liquid-solid chromatography. Owing to the adsorption of solvent on the surface of both silica and bonded phases, however, the physical chemical characteristics of the separation are more akin to a liquid-liquid distribution system than that of a liquid-solid system. As a consequence, although most modern stationary phases are in fact solids, solute distribution is usually treated theoretically as a liquid-liquid system. 

Beta SiC (PSiC) has good chemical resistance, particularly to oxidation owing to the formation of a thin adherent and protective film of silicon dioxide on the surface. Its characteristics are summarized in Table 9.6. 

The chain architecture and chemical structure could be modified by SCVCP leading to a facile, one-pot synthesis of surface-grafted branched polymers. The copolymerization gave an intermediate surface topography and film thickness between the polymer protrusions obtained from SCVP of an AB inimer and the polymer brushes obtained by ATRP of a conventional monomer. The difference in the Br content at the surface between hyperbranched, branched, and linear polymers was confirmed by XPS, suggesting the feasibility to control the surface chemical functionality. The principal result of the works is a demonstration of utility of the surface-initiated SCVP via ATRP to prepare surface-grafted hyperbranched and branched polymers with characteristic architecture and topography. 

Main physico-chemical characteristics of the solids weight percents of metals and additives, specific surface area, metallic dispersion. 

The physical and chemical characteristics of zinc oxide powders are known to affect cement formation (Smith, 1958 Norman et al., 1964 Crisp, Ambersley Wilson, 1980 Prosser Wilson, 1982). The rate of reaction depends on the source, preparation, particle size and surface moisture of the powder. Crystallinity and lattice strain have also been suggested as factors that may change the reactivity of zinc oxide powders towards eugenol (Smith, 1958). 

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