OBJECTIVES
- Prepare a PVOH film w/ a glutaldehyde deviation for film analysis
- Prepare clay samples w/ ratio and surfactant deviations for ion exchange experimentation
- Learn process of extracting and filtering out given magnetite (α – Fe3O4) sample in clay using vacuum filtration
Important Glutaldehyde Safety
- Glutaldehyde is toxic colorless liquid (100.12g / mole)
- Avoid all glutaldehyde skin contact by wearing gloves and googles
- Glutaldehyde should be kept in the freezer when not in use
- When in use, glutaldehyde should be kept in the fume hood
- Keep the glutaldehyde vial in a beaker so that it does not spill
- If spilled, wipe up glutaldehyde with paper towel while wearing gloves
- Keep all spills of glutaldehyde contained in the fume hood
- Wash hands after removing gloves that were in contact with glutaldehyde
Preparing Glutaldehyde Film
- In 10mL beaker, weigh out ~ 0.5 grams PVOH (MW 22K)
(Actual Mass = 0.5141g)
- Then, using a graduated cylinder add ~ 5 mL H2O to the beaker
- After adding and combining PVOH (MW 22K) in a small beaker with H2O, add a stir bar and prepare to stir solution
- On hot plate, stir and heat beaker solutions at 70-80°C for ~ 12 min or until PVOH dissolves
- Once PVOH solids thoroughly dissolve in solution, take the solution and place it in the fume hood
- Allow the solution to cool to 40-50°C in the fume hood, and then add 0.5 mL 8% glutaraldehyde to the solution
- Then pour the solution into a Teflon dish to sit, cool, and dry in the fume hood for ~ 2 days
Preparations For Clay - Surfactant Exchange
(Important Information and Notes About Clay)
- Clay is made from silicon dioxide
- If ions within the clay are changed, then clay absorbance, color, and exchange functions are affected
(Such ions incldue: Al3+, Mg2+, and Fe2+ or 3+)
- In a 50mL Eerlenmeyer flask, weigh out ~ 2 grams of clay to do a 100% ion exchange with Bu3HdP+
(Actual Mass of Clay = 2.0095g)
- Next, complete calculations to determine how much Bu3HdP+ will be needed to complete 100% exchange
2.0095 g Na-MT x (92 meqv/100 g Na-MT) x (1 mol Bu3HdP+/1000 meqv) x (100/100)% x (507.65 g Bu3HdP+/1 mol Bu3HdP+) = 0.9385 g Bu3HdP+
(Actual Bu3HdP+ Mass = 0.9399g)
- Then add a stir bar along with ~ 25mL of both H2O and ethanol to the clay and surfactant (Bu3HdP+) mixture
- Afterwards, stopper the flask and begin stirring the solution on a stir plate for ~ 1 week
(Repeat the entire process again in order to complete a 50% ion exchange with clay and surfactant, Bu3HdP+)
- Complete calculations to determine how much Bu3HdP+ will be needed to complete 50% exchange
2.0046 g Na-MT x (92 meqv/100 g Na-MT) x (1 mol Bu3HdP+/1000 meqv) x (50/100)% x (507.65 g Bu3HdP+/1 mol Bu3HdP+) = 0.4682 g Bu3HdP+
(Actual Mass of Clay = 2.0046g)
(Actual Bu3HdP+ Mass = 0.4690g)
Preparations For Clay - α-Fe3O4 Exchange
- Weigh out ~2g of NaMT clay, ~0.78g of FeCl3, ~0.39g of FeSO42-, and ~20g of NaOH
(Actual NaMT Mass: 2.0046g)
(Actual FeCl3 Mass: 0.7824g)
(Actual FeSO42- Mass: 0.3900g)
(Actual NaOH Mass: 20.0800g)
- In a 100mL beaker, add and combine all of these solids into the beaker except for the NaOH
- Next, add 40mL of H2O and a stir bar to the beaker
- Place the beaker containing the clay solution on a stir plate to stir for ~20 minutes
- Once all of the solids begin to dissipate into solution, then slowly add the NaOH over a period of ~15 minutes
- After fully adding the NaOH to the solution, make observations and allow the mixture to stir for an additional 10 minutes
Notes
- When adding the α - Fe3O4 to the clay and surfactant, Bu3HdP+ solution, heat was released
- Also the solution color shifted from a pale milky yellow color to a mahogany brown - black color after the α - Fe3O4 addition
- Glutaldehyde is an extremely toxic substance; therefore, all films and solutions containing glutaldehyde remained in the fume hood.
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