XRD pattern of the deposited alumina powders and green body deposit.
Optical photographs of the tubular porous alumina ceramics prepared (a) without a mesh; and at various mesh sizes: (b) 0.1985 mm; (c) 0.3033 mm; (d) 0.4650 mm; (e) 0.6567 mm.
Table 1
The average values of pores size and the ratio of the pore size to the mesh size (Sp/Sm).
| Mesh size [mm] | Average pore sizes [mm] | Sp/Sm |
|---|---|---|
| 0.6567 | 0.5834±0.1148 | 0.88933 |
| 0.4650 | 0.4536±0.1124 | 0.97548 |
| 0.3033 | 0.3110±0.0840 | 1.02539 |
| 0.1985 | 0.2483±0.1251 | 1.25088 |
| without mesh | 0.2819±0.1015 | – |
Calculated electric field strength distribution on the gauze surface for different mesh sizes (a) no mesh; (b) 0.1985 mm; (c) 0.3033 mm; (d) 0.4650 mm; (e) 0.6567 mm.
Table 2
The differences of the electric field intensities between the mesh grids and holes in the gauzes with different mesh sizes.
| Mesh | Electric field intensity [V/mm] | ||
|---|---|---|---|
| size [mm] | Mesh grid/Eg | Mesh hole/Eh | ∆E = Eg – Eh |
| 0.6567 | 1283.7 | 522.66 | 761.04 |
| 0.465 | 1201.8 | 414.04 | 787.76 |
| 0.3033 | 1191.6 | 382.67 | 808.93 |
| 0.1985 | 1080.2 | 198.74 | 881.46 |
Optical photographs of surfaces with a deposit from suspensions containing different types of acids: (a) propionic acid, pH = 4.13; (b) hydrochloric acid, pH = 4.12; (c) nitric acid, pH = 4.13; (d) hydrochloric acid, pH = 2.78. The insets represent (a) the pore diameter distribution determined from the relevant optical photographs; (b) the optical photograph of the opposite surface (close to the gauze) of the green body.
The pH values variation during the deposition from suspensions with different acids.
Effect of the pH values and zeta potential on the deposited pore structures.