Ultrasound in solution

Henglein A (1956) The acceleration of chemical reactions of ultrasound in solutions of oxygen-rare gas mixtures. Naturwissenschaften (in German) 43(12) 277-278... 

The application of power ultrasound in solution drastically increases the rate of mass hansport of material to the solid surface. Figure 4 shows two voltammograms obtained at a 3-mm glassy carbon elechode for the reduction of 1.0 mM Ru(NH3)6Cl3 in aqueous solution with 0.1 M KCl as supporting elecholyte, which is a well-defined model voltammetric system ... 

Makino K, Mosobba MM, Riesz P (1982) Chemical effects of ultrasound in aqueous solutions. Evidence for OH and H by spin-trapping. J Am Chem Soc 104 3537-3539... 

The propagation of ultrasound in aqueous solution changes the environment and therefore new oxidation states may be expected. To verify the exact nature of action of ultrasound in this system, a series of experiments were carried out to confirm whether,... 

Misik V, Riesz P (1996) Nitric oxide formation by ultrasound in aqueous solutions. J Phys Chem 100(45) 17986-179948... 

Many workers have since tried ultrasound induced Fenton s reagent methods to degrade phenol. Papadaki et al. [83] reported the lower efficiency of Fenton s reagent for phenol degradation due to competition of both Fe2+ and ultrasound for H202, resulting in the reduction of concentration of Fenton s reagent in solution. 

Abstract Hazardous effects of various amines, produced in the environment from the partial degradation of azo dyes and amino acids, adversely affect the quality of human life through water, soil and air pollution and therefore needed to be degraded. A number of such studies are already available in the literature, with or without the use of ultrasound, which have been summarized briefly. The sono-chemical degradation of amines and in the combination with a photocatalyst, TiC>2 has also been discussed. Similar such degradation studies for ethylamine (EA), aniline (A), diphenylamine (DPA) and naphthylamine (NA) in the presence of ultrasound, Ti02 and rare earths (REs) La, Pr, Nd, Sm and Gd, in aqueous solutions at 20 kHz and 250 W power have been carried out and reported, to examine the combinatorial efficacy of ultrasound in the presence of a photocatalyst and rare earth ions with reactive f-electrons. 

Henglein A (1995) Chemical effects of continuous and pulsed ultrasound in aqueous solutions. Ultason Sonochem 2 S 115—S121... 

Tauber et al. [23] following the same method as Hart et al. but using tert-butanol as the methyl radical source, obtained a temperature of 3,600 K in 10 3 M /(77-butanol and reported, similar to Hart et al. that this temperature decreased with increasing /( / /-butanol concentration. More recently, this method was adopted by Rae et al. [24] and Ciawi et al. [25, 26] in aqueous solutions. Rae et al. examined the effect of concentration of a series of aliphatic alcohols, extrapolating a maximum temperature of about 4,600 K at zero alcohol concentration [24]. They also observed a decrease in temperature with increasing alcohol concentration, which correlated well with the alcohol surface-excess and SL measurements obtained in the same system. Ciawi et al. investigated the effects of ultrasound frequency, solution temperature and dissolved gas on bubble temperature [26],... 

The book offers a theoretical introduction in the first three chapters, provides recent applications in material science in the next four chapters, describes the effects of ultrasound in aqueous solutions in the following five chapters and finally discusses the most exciting phenomenon of sonoluminescence in aqueous solutions containing inorganic materials in subsequent two chapters, before ending with a few basic introductory experiments of sonochemistry and sonoluminescence in the concluding chapter. 

The synthetic chemist will be mainly concerned with reactions in solution and the effects of ultrasound in such cases are best summarised in terms of four different reaction types. 

P. Riesz, Free radical generation by ultrasound in aqueous solutions of volatile and non-volatile solutes. Advances in Sonochemistry, T.J. Mason (ed.), JAI Press, London, 1991, 2, 23. 

Akutin, M. S. Preparation of block and graft polymers through the action of ultrasound on solutions of polymer in monomer. International Symposium on Macromolecular Chemistry, Prague 1957. Preprints of papers. 

In early studies on the formation of hydrogen peroxide by ultrasound in water under various mixtures of oxygen and hydrogen, it has been found that the yield depends on the composition of the mixture in the complex manner. The intermediates during the formation of hydrogen peroxide are free radicals and free atoms, and the question arises whether the radicals can escape from the cavitation bubbles into the bulk solution. 

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