PMC:5551755 / 14234-15445 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/5551755","sourcedb":"PMC","sourceid":"5551755","source_url":"https://www.ncbi.nlm.nih.gov/pmc/5551755","text":"The pillared clays using the traditional methods (2 and 3) presented more intense (001) reflections compared to samples 1, 4, and 5; indicating a more organized structure of the lamellae. This more organized structure is reflected in the values of the basal spacing and the surface areas obtained (Table 4). Sample 1 presented the lowest values of surface area (142 m2/g) and basal spacing (16.8 Å) due to the amount of water used to expand the clay (100 mL). In methods 4 and 5, 500 and 900 mL of water, respectively, were removed before the stage of pillarization. As a consequence of this removal of water, these samples presented lower surface areas (149 m2/g) in comparison with PILCs obtained by methods 1, 3 and traditional (higher than 200 m2/g). Therefore, the amount of water used to expand the lamellae also exerts a great influence in the cationic exchange of natural clay cations by the prepared oligomers, translating into a decrease in surface area when fewer amounts of water (methods 4 and 5) are used. Similar results were obtained with samples 2 and 3, indicating that the minimum relation of clay/water to obtain materials with elevated basal space and surface area (above 200 m2/g) is 1/50.","tracks":[]}