Tasks for 19 September
- To begin new synthesis of PVA and 10% w/w PVA-Clay films
- To finish analysing PVA-Malachite green data
- To start analysis on X-ray
- To measure absorbance of Mercury and Arsenic by films
New film synthesis
- 1.0022 g 22,000 MW PVA were used to make the PVA polymer film
- 1.0044 g 22,000 MW PVA and 0.1104 g Na Montmorillonite were used for the synthesis of 10% w/w PVA-Clay polymer film.
Completing preparation of ionic liquid modified clay
Continued from Set. 17 2014
- Ground with mortar
- Stored in dissecator
Measuring the Absorbance of Mercury and Arsenic
Film
|
Solution
|
Empty glass vial (g)
|
Glass Vial + film (g)
|
Film weight (g)
|
PVA |
150 ppm As
|
13.0969 |
13.2069 |
|
|
100 ppm As
|
13.1262
|
13.2127
|
|
|
50 ppm As
|
13.1340 |
13.2340 |
|
|
150 ppm Hg
|
13.0145 |
13.1050 |
|
|
100 ppm Hg
|
13.0742 |
13.1521 |
|
|
50 ppm Hg
|
13.1254 |
13.2356 |
|
10% PVA-Clay |
150 ppm As
|
13.1197 |
13.2435 |
|
|
100 ppm As
|
13.0765 |
13.1374 |
|
|
50 ppm As
|
13.1298 |
13.2529 |
|
|
150 ppm Hg
|
13.1706 |
13.2172 |
|
|
100 ppm Hg
|
13.1208 |
13.1908 |
|
|
50 ppm Hg
|
13.1493 |
13.2317 |
|
- Note: in order to make up the specified dilutions (Table above) of As and Hg, dilutions of stock solutions were prepared.
- Eleni prepared the arsenic dilutions
- James and Madeleine prepared the mercury dilutions
- Dilutions:
- 0.0499 mol As/L × 74.921 g As/mol × 1000 mg/g = 3738.56 mg/L = 3738.56 ppm
- (3738.56 ppm)(V)=(150ppm)(50mL)
- (3738.56 ppm)(V)=(100ppm)(50mL)
- 1.34mL in 50mL volumetric
- (3738.56 ppm)(V)=(50ppm)(50mL)
- 0.668mL in 50mL volumetric
- 268 ppm Hg (13.4 mM HgCl2)
- (268 ppm)(V)=(150 ppm)(50mL)
- 27.98mL in 50mL volumetric
- (268 ppm)(V)=(100 ppm)(50mL)
- 18.66mL in 50mL volumetric
- (268 ppm)(V)=(50 ppm)(50mL)
- 9.33mL in 50mL volumetric
10 mL of each solution were poured into glass vials containing the PVA-polymer films
Second Analysis of UV-Vis MG data for PVA-polymer film
Used MG calibration curves obtained on Sept. 5 2014
- ε615nm=0.1293 M-1cm-1
- A=εbc.
Solving for concentration:
- PVA in 2ppm = 0.031/(0.1291 M-1)= 0.240 ppm MG remain in solution (rest absorbed by film)
PVA in
|
MG left in solution (ppm)
|
MG absorbed by film (ppm)
|
2 ppm MG
|
0.240
|
1.760
|
8 ppm MG
|
0.913
|
7.087
|
80 ppm MG
|
31.70
|
48.30
|
200 ppm MG
|
92.00
|
108.0
|
Note that 10 of MG solution were added per vial, so that 2 ppm MG = (1.760 mg MG/L)×0.010L=0.0176 mg MG/film <-- absorbed amount <br.>
The weight of the film submerged in 2 ppm MG solution was 0.1060 g. Refer to Sept. 12 2014 for further film weights.
- (0.0176mg MG/0.01060g film)=0.0166 mg MG/g film
- 8 ppm: 0.728 mg MG/g film
- 80 ppm: 4.49 mg MG/g film
- 200 ppm: 10.8 mg MG/g film
Measuring amount of MG absorbed onto glass vial
As in previous section, the molar absorptivity and calibration curve from Sept. 5 2014 were used. <br.>
80 ppm MG in glass vial control: 42.87 ppm were absorbed by glass (Calculations as show in previous section)
200 ppm MG in glass vial control: 88.63 ppm were absorbed by glass
|