Objectives
- Crosslink Na-MT films.
- Adjust the pH of CuSO4 solutions made on 2012/09/28, then take ISE measurements.
CuSO4 Standard, Na+ Standard, and Na-MT Filtrate Solutions
- Please refer to the ISE protocol on 2012/09/28 for how ISE measurements were taken.
- 3 mL of the solutions were added to 0.1 mL of ionic strength adjuster (4 M solution containing NaOH) to adjust the pH to a value between 8 and 10.
- The solutions were allowed to equilibrate with the electrode for 2 min.
- Dilutions of 5 mL each of 1, 5, 10, 15, and 20 ppm Na+ in pure H2O were made from a 1000 ppm Na+ solution, then ISE measurements were taken.
- Calculations
5 mL 20 ppm Na+ requires:
(1000 ppm Na+)V1=(20 ppm Na+)(5 mL)
V1=100 μL
5 mL 10 ppm Na+ requires:
(1000 ppm Na+)V1=(10 ppm Na+)(5 mL)
V1=50 μL
5 mL 5 ppm Na+ requires:
(1000 ppm Na+)V1=(5 ppm Na+)(5 mL)
V1=25 μL
5 mL 5 ppm Na+ requires:
(1000 ppm Na+)V1=(5 ppm Na+)(5 mL)
V1=25 μL
5 mL 1 ppm Na+ requires:
(1000 ppm Na+)V1=(1 ppm Na+)(5 mL)
V1=5 μL
CuSO4 Standard Solutions
| Concentration [ppm]
| pH
| ISE [mV]
|
| 1 | 9.52 | -215.5
|
| 2 | 9.48 | -207.5
|
| 5 | 9.47 | -207.9
|
| 10 | 9.43 | -211.7
|
| 15 | 9.45 | -151.1
|
Na+ Standard Solutions
| Concentration [ppm]
| ISE [mV]
|
| 1 | -147
|
| 5 | -158
|
| 10 | -145.5
|
| 20 | -132.3
|
100% CEC (Na-MT)-CuSO4 Filtrate
| Cu+2 Concentration [ppm]
| Time [min]
| pH
| ISE [mV]
|
| 7.4 | 1 | 9.53 | -201.2
|
| 10 | 1 | 8.47 | -174.1
|
| 7.4 | 5 | 9.52 | -200.5
|
| 10 | 5 | 8.45 | -172.5
|
| 7.4 | 10 | 8.51 | -172.3
|
| 10 | 10 | 9.53 | -199
|
50% CEC (Na-MT)-CuSO4 Filtrate
| Cu+2 Concentration [ppm]
| Time [min]
| ISE [mV]
|
| 7.4 | 1 | -172.7
|
| 10 | 1 | -171.4
|
| 7.4 | 5 | -174.8
|
| 10 | 5 | -174.2
|
| 7.4 | 10 | -168.9
|
| 10 | 10 | -172.8
|
Unmodified (Na-MT)-CuSO4 Filtrate
| Cu+2 Concentration [ppm]
| Time [min]
| pH
| ISE [mV]
|
| 7.4 | 1 | 8.37 | -128.2
|
| 10 | 1 | 8.45 | -142.1
|
| 7.4 | 5 | 8.47 | -112.7
|
| 10 | 5 | 8.5 | -99.2
|
| 7.4 | 10 | 8.44 | -138
|
| 10 | 10 | 8.44 | -134.5
|
|