Table 5.
Fluorine-, Oxygen-, Silicon- and Nitrogen-to-Carbon atomic ratio of the pristine PVDF membrane (p-PVDF), coated membranes with FAS/TEOS (Coat-TEOS) and FAS/APTES (Coat-APTES) and modified membranes with oxygen plasma activation at 15 W and 15 min and functionalised with FAS/TEOS (PO2-TEOS) and FAS/APTES (PO2-APTES) before and after its use in the long-term stability tests. Standard deviation ≤ 0.05.
| Before Stability Test | After Stability Test | |||||||
|---|---|---|---|---|---|---|---|---|
| Membrane | F/C | O/C | Si/C | N/C | F/C | O/C | Si/C | N/C |
| p-PVDF | 0.92 | - | - | - | 0.90 | - | - | - |
| Coat-TEOS | 0.95 | 0.02 | <0.01 | - | 0.94 | 0.02 | <0.01 | - |
| Coat-APTES | 0.95 | 0.03 | <0.01 | 0.03 | 0.91 | 0.04 | 0.01 | <0.01 |
| PO2-TEOS | 0.95 | 0.04 | 0.01 | - | 0.80 | 0.03 | <0.01 | - |
| PO2-APTES | 0.99 | 0.05 | 0.01 | 0.04 | 0.85 | 0.09 | 0.02 | 0.04 |