Ultrasonic treatment

Ethylenediamine (70,71), benzyl alcohol and acetone (72), ethylene glycol (73) and C2—C g carboxyUc acids (74) are claimed to increase the reactivity of cellulose toward acetylation. Sodium hydroxide and Hquid ammonia (71) are excellent swelling agents and have been used to activate cellulose before esterification. Ultrasonic treatment of cellulose slurries (75) reportedly swells the fibers and improves reactivity. 

When ultrasonic treatment was applied before treating with the UV light, a higher bacteria kill was obtained. 

The ductility of GRT-polyethylene blends drastically decreases at ground rubber concentration in excess of 5%. The inclusion of hnely ground nitrile rubber from waste printing rollers into polyvinyl chloride (PVC) caused an increase in the impact properties of the thermoplastic matrix [76]. Addition of rubber powder that is physically modihed by ultrasonic treatment leads to PP-waste ethylene-propylene-diene monomer (EPDM) powder blends with improved morphology and mechanical properties [77]. 

A considerable decrease in platinum consumption without performance loss was attained when a certain amount (30 to 40% by mass) of the proton-conducting polymer was introduced into the catalytically active layer of the electrode. To this end a mixture of platinized carbon black and a solution of (low-equivalent-weight ionomeric ) Nafion is homogenized by ultrasonic treatment, applied to the diffusion layer, and freed of its solvent by exposure to a temperature of about 100°C. The part of the catalyst s surface area that is in contact with the electrolyte (which in the case of solid electrolytes is always quite small) increases considerably, due to the ionomer present in the active layer. 

Recently, Somorjai, Yang et al. [143] examined this reaction over lwt.% Pt/SBA-15 utilizing an elaborate preparation protocol. Preformed Pt nanoparticle sols of five different mean sizes, obtained by alcohol reduction in the presence of a protecting polymer (PVP) were combined with SBA-15 silica exhibiting 9nm pores. After 3h low-power ultrasonic treatment, the Pt particles were evenly distributed throughout the pores of the support (Figure 12 (a)-(e)). 

The first step for the determination of PAHs is removal from the matrix by solvent extraction, which preferably is performed with boiling toluene or benzene (hot solvent extraction by refluxing see Jacob and Grimmer 1994), although other solvents (e.g. tol-uene/acetone, acetone, and dichloromethane) and other extraction procedures (ultrasonic treatment, Soxhlet extraction, and accelerated solvent extraction) can also be applied. 

Villamiel, M. and Jong, P. D. (2000a). Inactivation of Pseudomonas fluorescens and Streptococcus thermophilus in Trypicase Soy Broth and total bacteria in milk by continuous-flow ultrasonic treatment and conventional heating. /. Food Eng. 45,171-179. 

Ghasemi et al. [24] have obtained nanostructured Pb02 (50-100 nm) using [5-PbO precursor and in the presence of ammonium peroxydisulfate as an oxidant. Here, the ultrasonication dispersed and then cracked the [5-PbO particles, thereby increasing the contribution of their surface area. Such an ultrasonic treatment resulted in an enhancement in the oxidation of PbO to Pb02 has been observed. Ultrasonic waves also have been found to inhibit the formation of Pb02 particles larger than 150 nm. 

In order to check these results, Lutz et al. degraded polymer samples which had been isolated shortly before macrogelation, by ultrasonic waves [213]. Figure 38A shows the decrease of Mw and of the hydrodynamic diameter dz, measured by static and dynamic light scattering respectively, on ultrasonic treatment of a polymer of Mw = 2.2 X10. Both Mw and dz decrease first abruptly but then... 

Ultrasonic treatment of a mixture of elemental gallium and iodine in toluene yields a light green insoluble product described as gallium(I) iodide [36], However, it now seems to be dear, as a result of several experimental observations, that a mixture of subiodides of gallium is actually formed. Nevertheless, the green powder behaves like Gal in many reactions and has also been employed for the synthesis of tetrahedral tetragallium dusters [Eq. (2)] [37, 38]. 

One impediment of universally applying PET in the area of packaging is its gas-barrier properties. These can be slightly improved by measures to increase the density (crystallinity) during blow molding, for example, by treatment with ultrasound. Ultrasonic treatment during injection reduces the gas permeability to a certain extent [34],... 

The first step of selectively depositing catalyst nanoparticies inside CNTs is their impregnation with a solution of the catalyst precursor. In the ideal case the solvent has a low surface tension, e.g., ethanol, to enable facile penetration into the CNT. Distilled water has also been reported for this purpose, however, with the aid of ultrasonic treatment [112]. The precursor solution can be added in excess or in defined volume. In any case, some weakly adsorbed metal species will remain on the outer CNT surface, which must be removed by washing with an appropriate solvent [111, 112]. A high selectivity to inside deposition is reported for this strategy, which is independent of the CNT diameter. 

Ogawa, T. and Ohkoshi, M. (1997). Properties of medium density fibreboards produced from thermoplasticized wood fibers by aUylation without adhesives. Mokuzai Gakkaishi, 43(1), 61-67. Ogiso, K. and Saka, S. (1993). Wood-inorganic composites prepared by sol-gel process II. Effects of ultrasonic treatments on preparation of wood-inorganic composites. Mokuzai Gakkasihi, 39(3), 301-307. 

The cells were harvested by centrifugation (10 min, 6500 g), washed with tris-S04 (10 him, pH 7.5), and resuspended in 10 ml of buffer A. All further steps were carried out at 4 °C to protect the enzyme against inactivation. A cell extract was prepared by ultrasonic treatment (8-10 times for 10 s) of the cell suspension, followed by centrifugation (40000g for 1 h). 

G.l. Eskin, Ultrasonic Treatment of Light Alloy Melts, Gordon Breach Science Publishers, Amsterdam, 1998, 4. 

Thixotropic. The ability of some colloidal gels to liquefy when subjected to shaking, vibration, or ultrasonic treatment and then to revert back to a gel or jelly-like form after time. 

The most convenient method is ultrasonic treatment with a subsequent solvent rinse of the surface. Other intermediate procedures are abrasive scrubbing, filing, or detergent cleaning. 

The nanostructures grown by SMPs were easily detached from the substrate by ultrasonic treatment, so the material can be dispersed into organic solvents and may be used for further preparation, chemical modification (etching), assembly and other nanochemical modifications. The SMPs seem to be promising candidates for the controlled growth of nanostructures, allowing us to circumvent the complexity associated with multi-parametric situations. 

The effect of surfactant on the dispersibility of Au nanoparticles depends on the sort of ionic type. When AOT was used instead of DOAC, the color of sols changed blue indicating the process of coagulation and the suspension was not stable. Within a few hours, the colloids fully precipitated. Figure 9-4.33 shows a TEM picture of this system sampled just after ultrasonic treatment to promote dispersion of sols. The particles in this picture are anisotropic and irregular in shape, and the size is larger than for the case of DOAC, as seen in the histogram. However, it is... 

It is known that mechanical disruption through milling or ultrasonic treatment occurs under creation of radicals located on the ruptured ends of the broken chemical bonds. 

Prepare a stable 1 1 (v/v) emulsion of an eluted glycoprotein (20-250 pg in a buffer, preferably PBS) and an adjuvant If Freund s complete adjuvant is used for the first intradermal injection, this can be done by subjecting the mixture in an Eppendorf tube to a short ultrasonic treatment (usually three to four pulses for 10-20 s each time). During sonication, the tube should be placed on ice. 

A procedure for the analysis of fruit for residues of postharvest preservatives and ethoxyquin was described by Gieger (132). Residues were extracted with dichloromethane via ultrasonic treatment. The extracts were analyzed on a C,8 5-/zm column, with methanol/0.01 M ammonium acetate (61 39) as a mobile phase adjusted to pH 7.5-7.7. Recovery for ethoxyquin was 65-78%, with a detection limit of approximately 0.05 mg/kg. 

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