the d-spacing of BTN was 1.7 nm (Fig. 1b). After chemical modification by using CTAB, strong evidence on 1° was observed. It can be calculated by using Bragg׳s law that the d-spacing of modified porous clay was to be 4.4 nm. The small angle region was observed and it was noted that structure of porous clay was significantly changed. The distance between layers was therefore extent.
• Download full-size imageDownload as PowerPoint slideThis was probably due to the fact that the chemical modification process was involved on surfactant template modification [2].
Fig. 2 exhibits the morphological properties of modified clay (Fig. 2b) and bentonite (Fig. 2a). The magnification of 80,000× was employed for observation. The microstructure of bentonite was significantly changed from plate-like structure to be porous. This was probably due to the reason that removal of cationic surfactant played an important role on extension of intercalation of silica plate, suggesting that chemical modification by using CTAB was successfully
• Download full-size imageDownload as PowerPoint slideThe nitrogen adsorption–desorption isotherm was investigated. The specific surface area was increased 100 m2/g. It was superior to bentonite which was only 30 m2/g. It was explained that significance on specific surface area can be observed due to removal of water and solvent in calcination process. The pathway of water and solvent was occurred and specific surface area was therefore obtained.