February 6, 2015
- MG absorption/rehydration trial
- PVA-Alg-Hectorite
Procedure
Procedure adapted from | Kuo-Ying Amanda Wu and Keith D. Wisecarver (1992)<br.>
Modified from 1/28/2015
- Prepare an aqueous solution of 13% PVA and 0.02% sodium alginate at 60°C (Stir plate on 3rd setting: ~68°C)
- 1 gram of PVA and 0.16 g of sodium alginate in 7 mL of water (12.5% PVA and ~0.02% alginate)
- Add alginate while stirring PVA-water solution
- ~0.1 g of nanocomposite should be added to this mixture where applicable
- Cool dissolved and mixed solution to 35°C
- Prepare 210 mL of saturated citric acid with 4% calcium chloride
- Add 8.4 grams (4%) of calcium chloride to 210 mL of water
- Add citric acid to saturation (32 g citric acid)
- 14.7g/100mL > 30.87 g/210 for solubility comparable to boric acid
- Add the PVA-Alg-Nanocomposite mixture drop-wise (by syringe) to the gently stirring (stir plate 3) citric acid-calcium chloride solution using a Pasteur pipette
- Stir for 2 hrs to allow solidification
- Rinse with water to remove excess reactants
Measurements
- PVA-Alg-Hectorite
- PVA: 1.003 g
- Alg: 0.161 g
- Hectorite: 0.105 g
- Citric acid: 12.751 g
- CaCl2: 8.414 g
- PVA-Alg-NaMT vial: 706 mg
- PVA-Alg-NaMT upscale synthesis: 1470 mg
Notes
- Rehydration attempt done on shaker, started at 12:28pm
- Beads on bottom of vial separate into individuals beads as they rehydrate
- Try lessening/removing citric acid
- Observation: beads that hold up seem to sink to the bottom where as the ones that fall apart float
List of Characterization Techniques
- UV-vis absorption (equilibrium measurements)
- DSC: wet >before and after dehydration (structure & cross-linking)
- pXRD dry (structure & cross-linking)
- FTIR/solvent washing (bonds)
- Microscopy: dry and wet (swelling, bead size)?
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