Tasks for September 24
- To continue processing films from last week
- To make new films with exfoliated clay
- To run AA on the arsenic samples.
Preparation of 10% wt new exfoliated clay films
- 1.0042 g 22,000 PVA, 0.1101 g of of exfoliated tributylhexadecylphosphonium bromide (THP Br) and 7 mL of distilled water were used to make up a 10% wt PVA-exfoliated THP Br film. Note this clay was prepared by Jame's group.
- 1.0028 g 22,000 PVA, 0.1107 g of exfoliated tributylhexadecylphosphonium bromide (THP Br) and 7 mL of distilled water were used to make up a 10% wt PVA-exfoliated THP Br film.
- Heated at approx. 80ºC with gentle stirring until all crystals were dissolved
- Allowed to cool down to room temeprature
- Added 0.8 wt% 0.5 mL glutaraldehyde under hood
- Stirred for 3 min to ensure homogeneity
- Poured into teflon dish and allowed to dry
Completing synthesis of films
- Soaked in sodium sulfate for 1h, put into 0.1% HCl, then sodium bicarbonate solution
Run AA on As samples
- James and Eleni made made As standards: 0, 10, 20, 30, 40 and 50 ppm.
- Diluted the 100 and 150 ppm As sample solutions so that:
- 150ppm(v1)=30ppm(10mL)
- v1=2 mL of 150 ppm As solution. To be diluted to 10 mL with distilled water.
- 100ppm(v1)=25ppm(10mL)
- v1=2.5 mL of 100 ppm solution. To be diluted to 10 mL with distilled water.
- Note: 50 ppm As solutions were left undiluted, as they were within the range of the range calibration curve
To be done at a later date since As lamp was burnt out
Measuring absorbance of Rhodamine dye by films
Film
|
Solution
|
Vial mass (g)
|
Vial + film mass (g)
|
Film mass (g)
|
PVA film |
20 μM R6G |
13.0803 |
13.1813 |
|
|
10 μM R6G |
13.0713 |
13.1497 |
|
|
2 μM R6G |
13.0403 |
13.1337 |
|
PVA-Clay film |
20 μM R6G |
13.0828 |
13.2554 |
|
|
10 μM R6G |
12.9552 |
13.0732 |
|
|
2 μM R6G |
13.0198 |
13.1377 |
|
|