Today's objective included the following:
- Try to create more clay-PVA beads.
- Make a calibration curve for our malachite green (MG).
- Prepare an additional PVOH film using clay solution instead of clay solid.
- Finish cross-linking films
1. Synthesis of PVOH-clay beads
2. MG calibration curve
We first diluted our 200ppm stock solution to the following dilutions: 20ppm, 10ppm, 2ppm, 1ppm, and 0.2ppm. However, our 20ppm and 10ppm dilutions gave us an absorbance greater than 1, so instead we substituted those two data points for 8ppm and 5ppm dilutions. Our UV Vis spectra and calibration curve can be seen found below.
3. Preparing PVOH films
Films of polyvinyl alcohol (PVOH, or PVA) were created using the following protocol:
- 1 g of PVOH, 3.33mL of 3% weight bentonite clay solution, 0.5mL of 8% glutaraldehyde, and 8.67 mL of DI water was heated, while stirring and covered with a watchglass, until al l PVOH crystals have been dissolved.
- After the crystals were completely dissolved the solutions were transferred to a Teflon dishes and placed in the fume hood to dry.
4. Cross-linking PVOH films
Film cross-linking from 9/07/2016 was only performed on two of the three films, so today we finished cross linking the third film. The procedure used can be found here.
Don't forget XRD analysis.
Don't forget these. They are very useful when you think about why your beads behave in a specific way.