Colloids, adsorption combinations

Willstatter s work on enzymes continued that of Emil Fischer (see p. 827). He used methods of adsorption and elution to obtain purer forms, which were increasingly unstable. He concluded that they consist of colloidal material combined with a chemically active group, but later research indicates that they are really individual proteins. The discovery of a number of enzymes has been mentioned in earlier chapters. The enzyme reductase in yeast was recognised and called philothion by J. de Rey-Pailhade. He found that if yeast is... 

The Adsorption of Arsenious Acid. — Biltz has studied the adsorption combination of arsenious acid with colloidal iron oxide. The complex was previously given a definite chemical formula and was regarded by Bunsen, who discovered that the hydrogel of iron was an... 

Adsorption phenomena from solutions onto sohd surfaces have been one of the important subjects in colloid and surface chemistry. Sophisticated application of adsorption has been demonstrated recently in the formation of self-assembhng monolayers and multilayers on various substrates [4,7], However, only a limited number of researchers have been devoted to the study of adsorption in binary hquid systems. The adsorption isotherm and colloidal stabihty measmement have been the main tools for these studies. The molecular level of characterization is needed to elucidate the phenomenon. We have employed the combination of smface forces measmement and Fomier transform infrared spectroscopy in attenuated total reflection (FTIR-ATR) to study the preferential (selective) adsorption of alcohol (methanol, ethanol, and propanol) onto glass surfaces from their binary mixtures with cyclohexane. Om studies have demonstrated the cluster formation of alcohol adsorbed on the surfaces and the long-range attraction associated with such adsorption. We may call these clusters macroclusters, because the thickness of the adsorbed alcohol layer is about 15 mn, which is quite large compared to the size of the alcohol. The following describes the results for the ethanol-cycohexane mixtures [10],... 

The sorbent materials are supplied as finely dispersed colloidal particles, whose surfaces are smooth. Some of their properties are presented in Table 3. The sorbents cover different combinations of hydrophobicity and sign of the surface charge. Thus, the model systems presented allow systematic investigation of the influences of hydrophobicity, electric charge, and protein structural stability on protein adsorption. 

The combination of foreign ions with the surfaces of colloidal particles is, in general, called adsorption. It goes without saying that this behaviour is not limited to small particles and that a large crystal of silver chloride can equally well adsorb positive or negative particles. 

Gougeon, R.D., Reinholdt, M., Delmotte, L., Miehe-Brendle, J., Chezeau, J.M., Le Dred, R., Mar-chal, R., Jeandet, P. (2002). Direct observation of polylysine side-chain interaction with smectites interlayer surfaces through H- A1 heteronuclear correlation NMR spectroscopy. Langmuir, the American Chemical Society Journal of Surfaces and Colloids, 18, 3396-3398 Gougeon, R.D., Soulard, M., Reinholdt, M., Miehe-Brendle, J., Chezeau, J.M., Le Dred, R., Mar-chal, R., Jeandet, P. (2003). Polypeptide adsorption onto a synthetic montmoriUonite A combined solid-state NMR, X-ray diffraction, thermal analysis and N2 adsorption study. Eur. J. Inorg. Chem., 2003, 1366-1372... 

Fig. 4.18. Procednre to make Pt particles separated from Pt dots by an alnmina interface (1) Adsorption of 530-nm PS particles on top of a Pt film on an alumina film, (2) melting of PS colloids to hemispheres, (3) Ar+ etching through the Pt film to the alumina layer, (4) further melting of the PS hemispheres, (5) deposition of a ceria layer, and finally, (6) liftoff of the PS spheres by a combination of a hot acetone bath and O2 plasma. The SEM image shows a 540-nm Pt particle surrounded by ceria with a thin separating alumina interface (from [91])...

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