Chemistry colloid

Some aspects of the history of colloid chemistry have been explored. There is a study of Isidor Traube (1860-1943), highlighting his work on molecular volumes of pure liquids and particularly on the apparent molar volumes of dissolved molecules 

A solution of table salt (NaCl) in water is called a true solution. The dissolved particles consist of single, hydrated ions and cannot be seen with the unaided eye. A suspension contains particles which you can often see with the naked eye and most certainly with the help of a microscope. Some examples of suspension are flour in water and muddy water. The particles of a suspension usually sediment (sink to the bottom) after a certain time and can easily be filtered off. In between the true solution and the suspension there is the colloidal dispersion, the particles of which are bigger than ions and molecules, yet too small to be detected by an optical microscope. The particle size in a colloidal dispersion lies between appr. 0.2 p (micron) and appr. 0.5 p (1 p = 10 6 m). 

According to the dictionary the word colloidal means gelatinous , but as we shall see later in this chapter, this term does not apply to most colloidal systems. 

Suspensions and colloidal dispersions differ from true solutions in that they are systems with more than one phase. This means that the substances present do not mix very well. The system is said to be heterogeneous and is characterized by interfaces between the phases, for instance between the water and a clay particle in muddy water. However, true solutions are one-phase systems and as a result homogeneous. In addition, they differ because in suspensions and dispersions the solid phase can be separated by means of filtration. 

Suspension can be filtered through filtering paper, colloidal dispersions through an ultra filter and true solutions cannot be filtered. A simple version of an ultra filter may look like this a membrane built in as the bottom of a suction funnel which, in its turn, is placed on a suction flask connected to a water jet pump. 

Particles of true solutions cannot be made visible. Colloidal particles 

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R. J. Good, R. L. Patrick, and R. R. Stromberg, eds.. Techniques of Surface arul Colloid Chemistry, Marcel Dekker, New York, 1972. 

K. J. Mysels, An Introduction to Colloid Chemistry, Interscience, New York, 1959. 

R. J. Pugh, Dispersion and Stability of Ceramic Powders, in Surface and Colloid Chemistry in Advanced Ceramics Processing, Marcel Dekker, New York, 1994, Chapter 4. 

See Colloid Chemistry, Theoretical and Applied, Reinhold, New York, 1944 also see Ref. 102. 

Ostwald W 1917 Theoretical and Applied Colloid Chemistry (London Chapman and Hall)... 

Bergna H E 1994 The Colloid Chemistry of Silica (Washington, DC American Chemical Society)... 

This thesis contributes to the knowledge of catalysis in water, us it describes an explorative journey in the, at the start of the research, unh odded field of catalysis of Diels-Alder reactions in aqueous media. The discussion will touch on organic chemistry, coordination chemistry and colloid chemistry, largely depending upon the physical-organic approach of structural variation for the elucidation of the underlying mechanisms and principles of the observed phenomena. 

W. A. Zisman, in K. J. Mysels and co-workers, eds., 20 Years of Suface and Colloid Chemistry, The Kendall Award Addresses, American Chemical Society, Washington, D.C., 1973, p. 109. 

H. Bergna, ed.. Colloid Chemistry of Silica, ACS Advances in Chemistry Series Number 234, ACS Books, Washington, D.C., 1994. 

C. E. Marshall, The Colloid Chemistry of the Silicate Minerals, Academic Press, Inc., New York, 1949. 

Dumansky Institute of Colloid Chemistry and Water Chemistry ofNASU ... 

Dumansky Institute of Colloid Chemistry and Water Chemistry ofNASU 42 Vernadsky blvd Kyiv-142 03680 Ukraine E-mail honch iccwc. kiev. ua... 

It is of special interest for many applications to consider adsorption of fiuids in matrices in the framework of models which include electrostatic forces. These systems are relevant, for example, to colloidal chemistry. On the other hand, electrodes made of specially treated carbon particles and impregnated by electrolyte solutions are very promising devices for practical applications. Only a few attempts have been undertaken to solve models with electrostatic forces, those have been restricted, moreover, to ionic fiuids with Coulomb interactions. We would hke to mention in advance that it is clear, at present, how to obtain the structural properties of ionic fiuids adsorbed in disordered charged matrices. Other systems with higher-order multipole interactions have not been studied so far. Thermodynamics of these systems, and, in particular, peculiarities of phase transitions, is the issue which is practically unsolved, in spite of its great importance. This part of our chapter is based on recent works from our laboratory [37,38]. 

R. Zsigmondy (Gottingen) demonstration of the heterogeneous nature of colloid solutions by methods which have since become fundamental in modem colloid chemistry. 

Kolloid-chemie,/, colloid chemistry, chemistry of colloids, -chemiker, m. colloid chemist. koUoidchemisch, a. coUoidochemical. KoUoiditat, /. colloidal quality. 

H. Van Olphen, An Introduction to Clay Colloid Chemistry, John Wiley Sons, Inc., N.Y. (1963). 

Problems which arise with certain precipitates include the coagulation or flocculation of a colloidal dispersion of a finely divided solid to permit its filtration and to prevent its re-peptisation upon washing the precipitate. It is therefore desirable to understand the basic principles of the colloid chemistry of precipitates, for which an appropriate textbook should be consulted (see the Bibliography, Section 11.80). However, some aspects of the colloidal state relevant to quantitative analysis are indicated below. 

Lipatov YuS (1984) Colloid chemistry of polymers, Naukova Dumka, Kiev... 

Rusanov AN (1973) In Advances in colloid chemistry, Nauka, Moscow, p 39... 

Classical surface and colloid chemistry generally treats systems experimentally in a statistical fashion, with phenomenological theories that are applicable only to building simplified microstructural models. In recent years scientists have learned not only to observe individual atoms or molecules but also to manipulate them with subangstrom precision. The characterization of surfaces and interfaces on nanoscopic and mesoscopic length scales is important both for a basic understanding of colloidal phenomena and for the creation and mastery of a multitude of industrial applications. 

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