Sonocrystallization ultrasound

Other emerging crystallization techniques, such as supercritical fluid crystallization and sonocrystallization (ultrasound in crystallization), are also mentioned. Potential applications for these emerging technologies are present in the pharmaceutical industry. 

Cavitation bubbles work as nucleation sites of particles. For example, in a supercooled sucrose solution, nucleation of ice crystals induced by cavitation bubbles has been experimentally observed [72], This phenomenon has been called sonocrys-tallization [73]. Although there are some papers on the mechanism of sonocrystal-lization, it has not yet been fully understood [74, 75]. It has been reported that the distribution of crystal size in sonocrystallization is narrower than that without ultrasound [73]. It may be related to the narrower size distribution of sonochemi-cally synthesized particles compared to that without ultrasound [76, 77]. Further studies are required for the mechanism of particle nucleation by ultrasound. 

Some of the reports are as follows. Mizukoshi et al. [31] reported ultrasound assisted reduction processes of Pt(IV) ions in the presence of anionic, cationic and non-ionic surfactant. They found that radicals formed from the reaction of the surfactants with primary radicals sonolysis of water and direct thermal decomposition of surfactants during collapsing of cavities contribute to reduction of metal ions. Fujimoto et al. [32] reported metal and alloy nanoparticles of Au, Pd and ft, and Mn02 prepared by reduction method in presence of surfactant and sonication environment. They found that surfactant shows stabilization of metal particles and has impact on narrow particle size distribution during sonication process. Abbas et al. [33] carried out the effects of different operational parameters in sodium chloride sonocrystallisation, namely temperature, ultrasonic power and concentration sodium. They found that the sonocrystallization is effective method for preparation of small NaCl crystals for pharmaceutical aerosol preparation. The crystal growth then occurs in supersaturated solution. Mersmann et al. (2001) [21] and Guo et al. [34] reported that the relative supersaturation in reactive crystallization is decisive for the crystal size and depends on the following factors. 

Castro M, Capote P (2007) Ultrasound-assisted crystallization (sonocrystallization). Ultrason Sonochem 14(6) 717-724... 

Ruecroft, G., Hipkiss, D., Ly, T., Maxted, N., and Cains, PW. 2005. Sonocrystallization The use of ultrasound for improved industrial crystallization. Organic Process Research Development, 9 923-32. 

Ultrasound-assisted formation of a solid phase sonocrystallization and sonoprecipitation... 

Sonocrystallization is the currently accepted name for the use of power ultrasound to control and accelerate the course of a crystallization process. This effect had previously been used in the salting-out process for years, and has been found to have a favourable... 

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