| Mineral: |
Kaolinite |
| Reference: |
AJW98 |
| SCM Type: |
CC - Constant Capacitance
(C1: 1.8 F/m2) |
| Ionic Strength: |
0.005 mol/L of
KNO3
|
| Site Type: |
»Al-OH |
| PZC: |
|
| pK1: |
4.9 |
pK1°I=0 (Conversion to I = 0): |
4.87 |
pK12.31 nm−2 (normalized): |
4.88 |
| pK2: |
7.19 |
pK2°I=0 (Conversion to I = 0): |
7.16 |
pK22.31 nm−2 (normalized): |
7.21 |
| Site Density in nm-2: |
2.2282 |
| Original Site Density: |
3.7 µmol / m² surface
|
| Solid/Liquid Ratio in g/L: |
6.38 |
| pH Range: |
3.5-9 |
| Temperature in K: |
343.15 |
| Method for Site Density: |
Sorption Isotherms |
| Method for Protolysis: | Potentiometric Titration |
| Fit Method: | FITEQL |
| Comment: |
2 distinct populations of adsorption sites on the kaolinite surface: relatively sparse ion-exchange sites on the siloxane faces XH (significant adsorption between pH 3 and 5) and more closely spaced variable-charge hydroxyl sites SOH (probably aluminol groups at crystal edges); total SSD=5.5µmol/m^2 {SOH} = 3.7+-0.1 µmol/m2 and {X-} = 2+-0.1 µmol/m2; cation exchange on the siloxane faces =SiH + K+ = =SiK + H+: titration with 0.1M HNO3 and 0.1M NaOH |
| |
