Sonication, 2-114 sulfuric acid

Descriptions of sulfuric acid analytical procedures not specified by ASTM are available (32,152). Federal specifications also describe the requited method of analysis. Concentrations of 78 wt % and 93 wt % H2SO4 are commonly measured indirectly by determining specific gravity. Higher acid concentrations are normally determined by titration with a base, or by sonic velocity or other physical property for plant control. Sonic velocity has been found to be quite accurate for strength analysis of both filming and nonfuming acid. 

Sonic agglomerators, which have been used experimentally for sulfuric acid mists and as mist eliminators. Commercial development is not projected at this time because the energy requirements are considerably greater than those for venturi scrubbers of similar capacity. 

Cleaning of SPR glass slides (optical grade SF2, refractive index 1.65, from UQG Optical Components). Sonicator (e.g., Lucas Dawe sonication bath) and different solutions hydrochloric acid/nitric acid 3 1 v/v (solution A) ammonium cerium nitrate (1M) (solution B) sulfuric acid/hydrogen peroxide 1 1 (Piranha solution) isopropanol. Use caution in handling these solutions harmful and corrosive. 

To determine intracellular polysaccharide, 100 mg of powdered dry hairy roots was suspended in 10 mL of distilled water, sonicated for 1 h, and centrifuged twice at 5030y for 10 min. The collected supernatant was used to determine intracellular polysaccharide by the phenol-sulfuric acid method (19). 

Yates group [67] used IR spectroscopy, temperature-programmed desorption, and mass spectrometry to study Xe adsorption on purified and cut SWNTs. The nanotubes were cut by subjecting them to a mixture of sulfuric and nitric acid treatment, followed by sonication with sulfuric acid and peroxide. Infrared (IR) measurements determined the presence of carboxylic acid and quinone groups on the treated tubes. Mass spectrometry of treated tubes heated under vacuum determined the evolution of different groups from the tubes as the temperature increased (CH4, CO, H2, and CO2). 

Aliphatic-aromatic polyamide can be grafted with modified carbon nanotubes by an in situ direct polycondensation technique [59]. The carbon nanotubes are treated by a mixture of concentrated sulfuric acid and nitric acid. This mixture is sonicated at 50 °C for 3 h in an ultrasonic bath. Subsequently the nanotubes are amino-fiinctionalized with 1,2-diaminoethane. Grafting significantly increases the thermal stability and improves the flame retardancy of the material. 

The same reaction, catalyzed by sulfuric acid, was studied in a continuous tubular sonicated reactor (Fig. 11), assembled in a pilot plant, as shown in Fig. 12. Constant conditions were chosen for inuline and catalyst concentrations (1 g/L and 37.1 g/L respectively). In this case, the temperature was changed from 40 to 80°C in steps of 10°C. The second-order reaction rate constant increases from sonicated to silent conditions by 60, 40, 20, and 6% by changing the temperature from 40 to 70°C at 80°C the increase is about 25%. 

Using a lead cathode in dilute methanolic sulfuric acid at a constant current of 20 mA cm 2, the benzyl alcohol was the major product from an unstirred solution. Mechanical stirring favors the hydrodimer, but sonication (cleaning bath, 100 W, 36 kHz) so strongly favors this product that the alcohol was barely evident. The magnitude of the effect depends on the ultrasonic power, however without appreciable stereochemical change. For benzaldehyde there are always imidentified products ca. 30%), whether the reaction is sonicated or not. 

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