Special Effect Inducers

Special effect inducers are additives that are used to help the coating meet special or unusual requirements. Examples include  

Bentley, J., Organic film formers, in Paint and Surface Coatings Theory and Practice, Lamboume, R., Ed., Ellis Horwood Limited, Chichester, 1987. 

Eorsgren, A., Linder, M. and Steihed, N., Substrate-polymer compatibility for various waterborne paint resins. Report 1999 IE, Swedish Corrosion Institute, Stockholm, 1999. 

Bilhneyer, F.W., Textbook of Polymer Science, 3rd ed., John WUey Sons, New York, 1984, 388. 

Potter, T.A., Rosthauser, J.W. and Schmelzer, H.G., in Proc., 11th International Conference Organic Coatings Science Technology, Athens, 1985, Paper 331. 

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The reduction and oxidation of radicals are discussed in Chapter. 6.3-6.5. That in the case of radicals derived from charged polymers the special effect of repulsion can play a dramatic role was mentioned above, when the reduction of poly(U)-derived base radicals by thiols was discussed. Beyond the common oxidation and reduction of radicals by transition metal ions, an unexpected effect of very low concentrations of iron ions was observed in the case of poly(acrylic acid) (Ulanski et al. 1996c). Radical-induced chain scission yields were poorly reproducible, but when the glass ware had been washed with EDTA to eliminate traces of transition metal ions, notably iron, from its surface, results became reproducible. In fact, the addition of 1 x 10 6 mol dm3 Fe2+ reduces in a pulse radiolysis experiment the amplitude of conductivity increase (a measure of the yield of chain scission Chap. 13.3) more than tenfold and also causes a significant increase in the rate of the chain-breaking process. In further experiments, this dramatic effect of low iron concentrations was confirmed by measuring the chain scission yields by a different method. At present, the underlying reactions are not yet understood. These data are, however, of some potential relevance to DNA free-radical chemistry, since the presence of adventitious transition metal ions is difficult to avoid. 

With respect to a risk assessment relevant to humans, toxic or biological manifestations in the lower dose ranges are of special interest, and LD50 or ED50 values or effects induced by highly toxic dose are of minor importance. 

Ion pair separation can also be facilitated by utilizing salt effects [2,6,16]. The basic principle is exemplary illustrated in Sch. 4 for a special salt effect induced by the addition of e.g., lithium perchlorate (generally in a polar solvent like acetonitrile). Applying this procedure, the primarily formed radical ion pairs (either as contact or solvent separate ion pairs) are subsequently replaced by the formation of a new and tight ion pair between the acceptor radical anion (A -) and lithium cation (Li+). PET reactions often proceed solely under these condition, e.g., when using ketones as PET-sensitizers [16]. 

The study of the effects induced by ion irradiation of solid materials, in particular solid carbons, is relevant in many fields of science and technology. Here we focus on its relevance in astrophysics. Solid carbon-bearing species are extremely abundant in space both in the gas and in the solid phases. A wide variety of solid carbons are observed in the interstellar and circumstellar medium as well as in many objects of the Solar System including those collected at or nearby Earth (interplanetary dust particles and meteorites). Observed and/or predicted carbon-bearing solids (or large molecules) include species with different hybridizations (sp, sp, sp" ) such as amorphous carbons, polycyclic aromatic hydrocarbons, fullerenes, nanodiamonds, graphite, and carbon chain molecules. The literature in the field is enormous interesting reviews can be found in a recent special volume of Speetroehimica Acta [1]. 

The merit of the generalized SCRF theory is that it correctly describes polarization effects on the solute subsystem which may be important, e.g. in enzymatic reactions. The fact that the solute nonlinear Schrodinger equation is explicitly solved, allows one to have special solvent induced electronic states, which could appear otherwise as excited states for the isolated system. 

Most of the chemical properties of tritium are common to those of the other hydrogen isotopes. However, notable deviations in chemical behavior result from isotope effects and from enhanced reaction kinetics induced by the ( -emission in tritium systems. Isotope exchange between tritium and other hydrogen isotopes is an interesting manifestation of the special chemical properties of tritium. 

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