CTAB surface area

This method gives a specific surface area contained in micropores of carbon black. The micropores cannot be penetrated by hexadecyltrimethylammonium bromide 

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See also Cetyltrimethylammonium bromide (CTAB) surface area antimicrobial used in cosmetics, 7 847 cosmetic surfactant, 7 834t Cetus, 11 12 Cetyl alcohol, 22 756 properties of commercial, 2 llt Cetyl bromide, physical properties of, 4 350t... 

CTAB surface area m2/g ASTM D 3765 ISO 6810 adsorption of CTAB (cetyl trimethyl ammonium bromide) from aqueous solution as a measure of the specific outer surface area... 

Figure 7.21. Bound rubber vs. CTAB surface area for various carbon blacks at 50 phr loading in SBR. [Adapted, by permission, from Wolff S, Wang M-J, Tan E-H, Ruhh. Chem. Technol., 66, No.2, 1993, 163-77.]...

CTAB surface area characterization is not influenced by micropores because of the size of CTAB molecule, but it ean be influeneed by surface chemistry and impurities (Wampler et al., 1997). Henee, it tends to disappear and to be replaced by BKY/t-plot, which is much more reliable. 

D3765 Testing CTAB Surface Area of Carbon Black... 

Another standard industry method for surface area is based on the adsorption of cetyltrimethylammonium bromide (CTAB) from aqueous solution. This is ASTM method D3765-85 (2). This method measures the specific surface area of carbon black exclusive of the internal area contained in micropores that are too small to admit the large CTAB molecules. Eor mbber-grade nonporous blacks the CTAB method gives excellent agreement with nitrogen surface areas. 

Table 17.2 presents results of physical-chemical testing of the silica powders. The A1 sample has the lowest Cetultrimethyammonium bromid (CTAB) and Brunaues, Emmett, and Teller (BET) surface area, higher structure (DBF) and more silanol (-OH) groups on surface per unit area. 

Table 2.7 lists techniques used to characterise carbon-blacks. Analysis of CB in rubber vulcanisates requires recovery of CB by digestion of the matrix followed by filtration, or by nonoxidative pyrolysis. Dispersion of CB within rubber products is usually assessed by the Cabot dispersion test, or by means of TEM. Kruse [46] has reviewed rubber microscopy, including the determination of the microstructure of CB in rubber compounds and vulcanisates and their qualitative and quantitative determination. Analysis of free CB features measurements of (i) particulate and aggregate size (SEM, TEM, XRD, AFM, STM) (ii) total surface area according to the BET method (ISO 4652), iodine adsorption (ISO 1304) or cetyltrimethylammonium bromide (CTAB) adsorption (ASTM D 3765) and (iii) external surface area, according to the dibutylphthalate (DBP) test (ASTM D 2414). TGA is an excellent technique for the quantification of CB in rubbers. However, it is very limited in being able to distinguish the different types of... 

Calculate the surface energies of each of these liquids and plot a graph of y for the CTAB solutions as a function of logio(conc.). Use your results and the Gibbs adsorption equation (see later) to estimate the minimum surface area per CTAB molecule adsorbed at the air-water interface. 

In summary, nanometer-sized mesoporous silica and alumina spheres with tunable diameters (80 - 900 nm) can be synthesized in organic solvent. Mesoporous silica spheres templated by cationic surfactant (CTAB) have hexagonal array with monodispersed pore size (-2.4 nm), high surface areas (-1020 m2/g), and pore volume (1.02 cm3/g). Mesoporous alumina spheres templated by amphiphilic triblock copolymer show a large disordered mesopore (10.0 nm) and high BET surface area (360 m2/g). 

In summary, textural parameters that are essential for the catalysts performance were prepared from variable combinations of CTAB/NH4OH/ H20 in the presence of co-surfactants, i.e. acetone and the light alcohols (MeOH, EtOH, PrOH). The resuts indicate that the porous structure of the materials thus obtained are maintained along the distinct TEOS and CTAB concentration ratios, even with the influence of diverse co-surfactants. Then, the textural properties of the mesoporosus MSS, measured by N2 adsorption, indicate a reproducibility of the textural properties, i.e. pore volume, mean pore size distribution and total surface area (Figure 15.8). 

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