A Crystallite Packing Model for Pseudoboehmite Formed during the Hydrolysis of Trisecbutoxyaluminium to Explain the Peptizability

Gallium-Doped Boehmite Nanotubes and Nanoribbons. A TEM, EDX, XRD, BET, and TG Study

“…These broad peaks are attributed to a poorly diffracting phase. This poorly diffracting phase is probably pseudoboehmite . The peak position for the precipitate samples shifted to a higher degree 2θ with the increase in Ga content, ranging from 7.72 to 8.56° 2θ; in contrast, the peak position for the samples hydrothermally treated for 6 days shifted to lower degrees 2θ with the increase in Ga content, ranging from 8.25 to 8.98° 2θ.…”

“…41 The peak position for the precipitate samples shifted to a higher degree 2θ with the increase in Ga content, ranging from 7.72 to 8.56°2θ; in contrast, the peak position for the samples hydrothermally treated for 6 days shifted to lower degrees 2θ with the increase in Ga content, ranging from 8.25 to 8.98°2θ. The d(020) spacing 40,41 for the 4, 5, 10, and 20% Ga-doped boehmite after hydrothermal treatment were 9.84, 10.01, 10.33, and 10.70 Å, respectively. The results of the EDX show that the nanotubes have an identical composition to that of the poorly diffracting material, as is observed in the TEM images.…”

Effect of vacuum and of strong adsorbed water films on micropore formation in aluminum hydroxide xerogel powders

“…If so, our S BET data predict that the interactions between ethanol and water are almost the same (Table 1) as those between methanol and water and between isopropanol and water. A number of studies [36][37][38][39][40] show that this inference should hold only for methanol and ethanol, but not for isopropanol. Indeed, for the systems ethanolwater and methanol-water the heat of solution at infinite dilution is 0.2 and 0.3 kJ/mol, respectively, but for isopropanol-water mixture, under the same conditions, a value of about 0.014 kJ/mol can be estimated.…”

A Reliable Method for the Preparation of Multiporous Alumina Monoliths by Ice-Templating

“…Hence, insufficient peptization duration or temperature may affect the overall mesostructuration of the material. Amorphous aluminium hydroxide is formed at room temperature, whereas temperatures above 85˝C are needed to form pseudoboehmite [11,42]. The boehmite crystallite size increases linearly with time until peptization, which inhibits further growth.…”

“…An ageing step of 1 h was maintained prior to peptization to ensure complete hydrolysis of the alkoxide while keeping boehmite crystallite size small enough to fit into inter-micellar voids. Martens et al [42] proposed that the peptization mechanism is linked to the particle growth as platelets before peptization and their further stacking. Faster peptization leads to increased surface area and larger interparticle porosity.…”