Alkaline–acid treated mordenite and beta zeolites featuring mesoporous dimensional uniformity

Synthesis and Characterization of Novel Catalytic Materials Using Industrial Slag: Influence of Alkaline Pretreatment, Synthesis Time and Temperature

“…Alkaline pretreatment as one of the ways of treatment is a well-known procedure of desilication, promoting formation of the mesoporous structure [18][19][20][21]. In contrast to the acid treatment, alkaline treatment promotes selective extraction of framework Si atoms with creation of uniform-sized mesopores without changes in the crystallinity [18,19].…”

“…In contrast to the acid treatment, alkaline treatment promotes selective extraction of framework Si atoms with creation of uniform-sized mesopores without changes in the crystallinity [18,19]. Formation of mesopores and a significant increase of the surface area were observed during the alkaline treatment of zeolites [20,21].…”

Mesopore modification of beta zeolites by sequential alkali and acid treatments: Narrowing mesopore size distribution featuring unimodality and mesoporous texture properties estimated upon a mesoporous volumetric model

“…11), the crystallinity and weight yield relative to the parent were confirmed to reduce to 50% and to ~44%, respectively, with increasing alkaline concentrations, though having a dramatic increase in mesopore volume. Evidently, continuous desilication upon the concentrated alkaline treatment brought about an obvious loss of yield and crystallinity regardless of a minor effect of dealumination under the same acid leaching condition at 353 K. In contrast to zeolites MFI [24] and MOR [50], a lower stability and hence a higher derogation degree of BEA structure was also found to correlate with the poor crystallinity and yield. Moreover, the gradual increase in mesoporosity could be explained by the Si and Al extraction from BEA framework, followed by the removals of amorphous Al-rich species formed [51], after sequential alkaline and acid treatments.…”

Dispersability of Carbon Nanotubes in Biopolymer-Based Fluids

“…ζ-potential is obtained from electrophoretic mobility values [24]. Smoluckowski's approximation holds, since the electrical double layer thickness around particles, δ, is much lower than the hydrodynamic radius [25].…”

“…It must be kept in mind that the acidity and hydrophobicity of inorganic surfaces play a substantial role in the interaction with biopolymers. What is more, the local topology induced by manufacturing nanoparticles, such as chemical functionalization [25], thermal cycling [26], or milling [27], are more relevant in favoring adsorption than chemical composition.…”