Ultrasonic disaggregation

Ultrasonic disaggregation Add a sufficient amount of dispersant solution (10% sodium hexametaphosphate solution, or Calgon, is most commonly used see Lewis McConchie, 1994, for a list of others) to bring the volume to about 50-100 ml (depending on the size of the centrifuge to be used) and put the sample into an ultrasonic bath for 10 to 30 minutes. 

Dithiocetals, thioglycosides preparation, 181 DNA, disaggregation, ultrasonic irradiation, 11 Double bonds, unsaturated monosaccharides,... 

If particles are aggregated after the opsonization procedure, vortex the particles vigorously. If vortexing does not disaggregate the particles, then place the tube containing the particles in an ultrasonic cleaning bath for 10 min. 

Barj et al." and Pommier et al. examined thermal decomposition of Mg[Al(0-iec-Bu)4]2 in ethanol decomposition starts at 283°C, yielding an essentially amorphous product, while the reaction at 360°C yields partially crystallized MgAl204 spinel. The product consisted of secondary particles with a size of 3 pm, which is easily disaggregated by ultrasonic treatment into 0.02 pm primary particles. They also reported that thermal dehydration of ethanol becomes significant at temperatures higher than 360°C. Therefore crystallization of this product seems to occm with the aid of water formed by dehydration of the solvent. 

Resuspend in 70% ethanol, disaggregate in French pressure cell, ultrasonicate and wet sieve. 

High-intensity ultrasonication can be considered as a mechanical method for producing cellulose nanofibers with hydrodynamic forces [72]. In this process, ultrasonic waves create strong mechanical stress because of cavitations, and therefore, cause the disaggregation of cellulosic fiber to nanofibers [73]. Several attempts have been made to isolate cellulose nanofiber by ultrasonication from various cellulose sources such as microcrystalline cellulose, regenerated and pure cellulose fibers [72], kraft pulp [74], flax, wood, wheat straw and bamboo [75] (Figure 11.5), para rubberwood sawdust [76], and poplar wood powders [15]. 

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