Abstract
Morphological and surface analysis was performed on titanosilicate ETS-4 crystals using atomic force microscopy (AFM) and field emission scanning electron microscopy. Crystals were synthesized hydrothermally at 175 °C in Teflon-lined stainless steel autoclaves using organic precursors. Rectangular and plate shaped crystals were formed with the largest crystals being 2×20×5 μm and 2×10×10 μm, respectively. EDX analysis revealed a disparity between the Si/Ti ratio in crystals characterized by different morphologies (2.5 for rectangular vs. 2.8 for plates). Growth occurred on the slowest growing and the largest crystal via a layer mechanism. Spiral hillocks were found on {100} surfaces of rectangular shaped crystals and on the largest faces of intergrown plate crystallites. Steps on these surfaces were observed to emanate from spiral hillocks and had a step height of 1.10±0.15 nm. The crystallographic d-spacing of the (200) plane, as measured by powder X-ray diffraction, correlated with the AFM measured step height.
| Original language | English |
|---|---|
| Pages (from-to) | 71-76 |
| Number of pages | 6 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 69 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Apr 8 2004 |
Keywords
- Atomic force microscopy
- ETS-4
- Step height
- Surface structure
- Titanosilicate