To conduct ion conductivity tests on the 100% CEC clay, to make a new 1 g glutaraldehyde/PVOH film, to crosslink the porphyrin film, and to conduct UV-Vis tests on the copper solution
Ion Conductivity Test
- Secure the 100% CEC film in the osmosis apparatus.
- Fill the left side of the apparatus with water and ensure that no liquid leaks through the film. Then fill the right side of the apparatus with salt solution. Record the starting levels of each side.
- Place an electrode in each side.
- Record the conductivity every 5 minutes for the first hour, then once each hour afterwards.
- Leave the film in the apparatus until Wednesday.
- On Wednesday, measure the conductivity one final time and then remove the film from the apparatus.
Porphyrin Film Crosslinking
- The exact amounts of glutaraldehyde fixant, HCl, and sodium bicarbonate solutions were recorded. A sample of the solutions were saved before and after crosslinking for tests with UV-Vis.
- Allow the PVOH film containing glutaraldehyde to dry completely.
- Prepare a solution of 100 mL H2O, 2 mL concentrated H2SO4, and 20 g Na2SO4 in a 150 mL beaker. (solution is referred to as glutaraldehyde fixant)
- Place stir bar in beaker and a Buchner funnel top (cap) over the stir bar
- Heat solution to 70°C (temperature on hotplate should be about 160)
- Place film in solution for one hour.
- Prepare 100 mL of a 1% HCl solution in a 150 mL beaker. Place a stir bar and an inverted buchner funnel into beaker.
- Heat HCl solution to 70°C
- Remove film from glutaraldehyde fixant and rinse with distilled water.
- Place film into HCl solution for 30 minutes.
- Prepare 0.2 M sodium bicarbonate solution. (1.68 g in 100 mL)
- After 30 minutes, remove the film from the HCl solution and place into the sodium bicarbonate solution (at room temperature) for about 15 minutes.
- Use tweezers to remove the film from the sodium bicarbonate solution.
- Rinse film with deionized water and place in a beaker with distilled water until it is used.
- 100 mL of glutaraldehyde fixant, 1 mL HCl in 100 mL water, and 1.6817 g sodium bicarbonate in 100 mL water were used.
Glutaraldehyde Film Preparation
- 1 g of PVOH was weighted out and dissolved in 7 mL of water in a small beaker with a stir bar.
- The beaker was placed on a hotplate and was heated to allow the PVOH to dissolve into the water.
- 1 mL of glutaraldehyde was added to the PVOH.
- The solution was stirred under the fume hood for 5 minutes.
- The gel was then poured into a dish and allowed to evaporate until Wednesday.
- UV-Vis was taken of the filtrates from the clay-copper sulfate exchange.
- Originally a PVOH/glutaraldehyde film was used, but it broke when placed into the apparatus
- Some leaking was observed in the osmosis apparatus
- The ion solution consists of 100 ppm Cl-, 100 ppm Br-, and 100 ppm SO42- all as Na+ salts