To crosslink the prepared glutaraldehyde film, make additional glutaraldehyde film and glutaraldehyde film with PDMS, prepare 500 mL of 20 ppm CuSO solution and NaSO4 solution, and dry clays
Crosslinking Glutaraldehyde Films
- 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 dry film on paper towel.
- Weigh film and record mass.
Preparing Glutaraldehyde Film
- 0.5 g PVOH was dissolved in 5 mL water on a heated hot plate.
- Once dissolved, 0.8% wt Glutaraldehyde solution (1 mL) was added.
- The gel was then poured into a plastic dish and was allowed to evaporate over the weekend.
Preparing PDMS Film
- Prepared as previous film but with 10% PVOH replaced with glutaraldehyde
- 0.4 g PVOH and 0.1 g PDMS were dissolved in 5 mL of water on a hot plate.
- Once dissolved, 1 mL of glutaraldehyde was added to the PVOH/PDMS
- The mixture was allowed to stir without heat for 3 minutes
- The film was poured into a dish and was left under the hood over the weekend
20 ppm CuSO4 and Na2SO4 Solution Preparation
- 500 mL of 20 ppm CuSO4 solution and 500 mL of 20 ppm Na2SO4 solution were prepared.
*200 g Na2So4, 1L H2O stirred to dissolution + 20ml H2 So4
*MW CuSO4 * 5 H20= 249.67 g/mole 20 ppm in 500ml H2O MW= 18 g/mol (500g of h20/18g/mol=27.7moles)
**27.7moles h2O* ((20moles cuso4*5H2O)/1,000,000 moles H2O) = 5.55 E -4 moles Cuso4*5molesH20
**5.55E-4moles CuSo4*5H2O * 249.68 g/mol= 0.1387g CuSo4*5H2O
**5.55E-4moles Na2SO4 * 142.04g/mol=0.078 (20ppm)
*we want 500ml of 20ppm = 20mg/l CuSO4
** x=36.05ml in total 100ml solution
* we want 500ml of 20ppm= 20mg/l Na2SO4
** 156.8 mg/l x = .5(20mg/L)v
** x= 63.78ml in total 100ml solution
Mass of glutaraldehyde film after crosslinking = 0.8059 g
- The copper sulfate and sodium sulfate solutions prepared were incorrect. See October 5 for correct calculations