Fumed alumina

Figure 2. Optical spectra of (dimethylamino) azobenzene, DMAAB, adsorbed onto individual fumed alumina, silica A-300, and titania, and mixed oxides Si02/Ti02 (37 wt% Ti02), Al203/Si02 (30 wt% A1203) and Al203/Si02/Ti02 (22, 28, and 50 wt% res-pecttively).

Transfer 1.0 g of fumed alumina nanoparticles to a 100-mL round-bottom flask. 

Fumed alumina SEM image (a) size distributions from TEM images, ultrasonic spectroscopy (USS), dynamic light scattering (DLS), and laser diffraction (LD) (b). 

F. Band between 3690 and 3675 cm. The relative intensity of this band is high in the spectra of fumed alumina samples. 

The so-called fumed aluminas are obtained by flame hydrolysis of AICI3. The high temperature reaction of AICI3 vapor in a H2/O2 flame yields very small, nonporous alumina particles (96) that are characterized by a low... 

Fumed aluminas have a peculiar morphology that is characterized by the absence of significant porosity. The phase composition of fumed aluminas has been found to vary, and different samples have been reported to consist of pure y-Al203 (188—190), pure 8-AI2O3 (186—191), or a mixture of Y-AI2O3 and 5-AI2O3 (186-192). TEM images of fumed aluminas... 

TEM shows fumed alumina rich in 8-AI2O3 to have a pronounced globular morphology, whereas 8-AI2O3 produced by calcination of boehmite essentially retains the morphology of the starting oxyhydroxide, such as lamellar, fibrous, or nanorod Hke (57,208). 

The band at about 3770 cm is characterized by the most complex behavior, and is found to be associated with the most reactive sites. It has been reported to be particularly intense in the spectra of highly reactive aluminas (98). This band is not present in the spectra of fumed aluminas that were activated in vacuum (97,98,286), but it appears if the activation of the fumed alumina includes a step in wet air (97,189), as shown in Figure 3.20 (97). On the basis of these results, the lack of a band at... 

FIGURE 2.48 Adsorption of different adsorbates onto (a) A-300 degassed at 200°C (b) fumed alumina (5bet,n2= 133 m /g) degassed at 200, 600, and 900°C and adsorption of (c) hexane and (d) acetonitrile onto A-50, A-200, alumina (5 bet,n2=89 m /g), and titania. (Adapted from J. Colloid Interface Sci., 348, Gun ko, V.M., G.R. Yurchenko, Turov, V.V. et al., Adsorption of polar and nonpolar compounds onto complex nanooxides with silica, alumina, and titania, 546-558, 2010d, Copyright 2010, with permission from Elsevier.)... 

Cabot Corporation 2011. Fumed silica and fumed alumina in coatings applications. http //www.cabot-corp. com/Silicas-And-Aluminas (accessed October 27, 2006). 

Gun ko, V.M., Zarko, V.L, Turov, V.V. et al. 1999b. Characterization of fumed alumina/sihca/titania in the gas phase and aqueous suspension. J. Colloid Interface Sci. 220 302-323. 

Electronic balance and weighing paper Fumed alumina nanoparticles (Degussa)... 

In particular, fumed alumina and fumed silica products provide tribo-charging, free-flow, fluidization and anti-blocking in powder coating applications. Typically, fumed alumina is used for tribo coating processes and either fumed silica or hexamethyldisilazane treated fumed alumina is selected for corona coating processes (3). 

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