Testing Bead Protocol of 11/4/2014
- Somehow, most of the beads get stuck in the organic phase. Also, additional stirring disrupts the beads and the added glutaraldehyde forms a sludge.
- I concluded that the problem might have been too much organic phase is being used for the amount of PVA-clay-HCl.
Measurements and Synthesis
- Running DSC on ribbons
- weighed out a tzero pan with a hermetic lid
- placed between 3-10 mg of ribbon in it
- seal it up
- Running Powder XRD on ribbons
- a section of ribbon was sliced and dried
- Testing absorption of ribbons over time
- a stock solution of 20ppm was prepared by Eleni
- a chunk of ribbon was weighed and placed in a scintillation vial with 10mL of 20.2ppm Malachite Green Solution
- Extractions were started at 9:20 taken initially and at 5, 10, 15, 30, 60, 90
- 50uL sample into 950uL of water
- Synthesis of Beads following Mary's protocol (original synthesis may be viewed here).
- Add 0.51520g PVA and 0.05154g Clay in 6 mL 10% HCl
- 750 uL of 0.8% glutaraldehyde was added to 20 mL of ethyl acetate. The mixture was stirred at maximum speed on a stirrer.
- The PVA-Clay-HCl solution was added to the ethyl acetate mixture in a drop wise manner.
- Depending on the conditions, microbeads should form between 2-3 minutes. As soon as the beads are visible, IMMEDIATELY ADD 25 mL of 0.2 M NaHCO3. Stir for at least 4 minutes, 15 minutes at most.
- Beads will be ready once a clear separation of the water and organic phase is observed. Beads will precipitate to the bottom of the beaker. There will still be some beads left in the organic solvent phase.
- Pour the contents into the falcon tube.
- Centrifuge for 1 min at 3000 rpm.
- Afterwards, remove the organic phase and suspend the beads in distilled water.