The Chemistry of Inorganic Surfaces

But perhaps more important than the physics behind these processes is the fact that they have been observed. 

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Chemistry is involved at every stage of the process, including the chemistry of inorganic pigments and organic resins, colloid and surface chemistry, as well as elements of environmental and analytical chemistry. The Chemistry of Paper provides an informative and entertaining overview of the chemical principles involved. It will be especially suitable to students and others who require an introduction to the chemistry of paper manufacture. 

The chemistry is both wide ranging and interesting. It involves carbohydrate chemistry, the chemistry of inorganic pigments, organic resins —both natural and synthetic—and many other organic and polymeric additives. The sheet formation process also involves a considerable amount of colloid and surface chemistry. Polymer chemistry and environmental and analytical chemistry also play an important part. 

Even though the vacuum-oriented surface techniques yield much useful information about the chemistry of a surface, their use is not totally without problems. Hydrated surfaces, for example, are susceptible to dehydration due to the vacuum and localized sample heating induced by x-ray and electron beams. Still, successful studies have been conducted on aquated inorganic salts (3), water on metals (3), and hydrated iron oxide minerals (4). Even aqueous solutions themselves have been studied by x-ray photoelectron spectroscopy (j>). The reader should also remember that even dry samples can sometimes undergo deterioration under the proper circumstances. In most cases, however, alterations in the sample surface can be detected by monitoring the spectra as a function of time of x-ray or electron beam exposure and by a careful, visual inspection of the sample. 

Differences are also noticed in the values of the surface pH and amounts of preadsorbed water. The pH values for the exhausted samples after subsequent SOj and HjS adsorption runs are much lower than those after HjS adsorption followed by SOj adsorption. This suggests differences in the surface reaction products. These differences are also reflected in the amount of water adsorbed after the first runs in the breakthrough tests. After SOj adsorption much more water is preadsorbed before the next run than after adsorption of HjS. This once again indicates differences in the chemistry of inorganic phase. After SO2 adsorption it is likely that still some oxides able to adsorb water are present (hydrophilic surface) whereas reactions with HjS and deposition of sulfur [12,14] almost totally "screen" active centers for water adsorption. 

A chief goal of this book is to help the reader understand controls on the chemical quality of surface-and subsurface-waters, both pristine and polluted. The focus is on inorganic processes and on the chemistry of soil and groundwaters, with less said about the chemistry of precipitation, surface-waters, or the ocean. The book leans heavily on the principles of chemical thermodynamics and the concept of chemical equilibrium. Chemical equilibrium, whether attainable or not, represents the reference state for purposes of explaining the concentrations of aqueous species in the hydrosphere. Concepts of chemical kinetics are introduced when they are known and seem applicable. 

Laboratory, where he worked with John Longo and Allan Jacobson on the synthesis and characterization of mixed metal oxides and their application in heterogeneous catalysis. He joined the chemistry faculty of Northwestern University in 1984 where he is now Professor of Chemistry and an active member of the Center for Catalysis and Surface Science and the Materials Research Science and Engineering Center. Kenneth Poeppelmeier has published over 250 research papers and supervised approximately 40 Ph.D. students in the area of inorganic and solid state chemistry. He is a Fellow of the American Association for the Advancement of Science (AAAS) and the Japan Society for the Promotion of Science (JSPS) and has been a Lecturer for the National Science Council of Taiwan (1991), Natural Science Foundation of China (1999) and Chemistry Week in China (2004), and more recently an Institut Universitaire de France Professor (2003). 

Pyrite is not only one of the key compounds in Wachtershauser s theory, but could also have fulfilled an important function for phosphate chemistry in prebiotic syntheses. A group in Rio de Janeiro studied the conditions for phosphate sorption and desorption under conditions which may have been present in the primeval ocean. In particular, the question arises as to the enrichment of free, soluble inorganic phosphate (Pi), which was probably present in low concentrations similar to those of today (10 7-10 8M) (Miller and Keffe, 1995). Experiments show that acid conditions favour sorption at FeS2, while a weakly alkaline milieu works in an opposite manner. Sorption of Pi can be favoured by various factors, such as hydrophobic coating of pyrite with molecules such as acetate, which could have been formed in the vicinity of hydrothermal systems, or the neutralisation of mineral surface charges by Na+ and K+. 

Similar to inorganic components, solid organic matter (SOM) plays a significant role in affecting the chemistry of solid phase surfaces. Humus and SOM can be considered as synonyms, and include the total organic compounds in solid... 

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