- Prepare PVA-clay microspheres.
- Run diffusion tests on hydrogels prepared on 2013/01/30 with Rhodamine 6G dye added on 2013/02/08.
- Due to the relatively unsuccessful preparation of PVA/clay microspheres(the prepared spheres were either larger than a micrometer or did not appear at all), a new method was used for the preparation of PVA/clay microspheres.
- The desired ratio of PVA and clay was measured out. The total mass was ~1g.
- The PVA/clay was placed in a 50mL beaker with a magnetic stir bar. 25mL distilled H2O were added to the beaker and the solution was heated to ~100°C and allowed to stir until complete dissolution of PVA/clay.
- The magnetic stir bar was removed and 25mL of mineral oil was added to the beaker.
- The contents of the beaker were poured into a blender to homogenize the solution and create an emulsion of the aqueous and organic layer in the attempt to create a suspension of microspheres.
- The blender was turned on a low setting for 5 minutes.
- The contents of the blender were poured into a beaker and the appropriate amount of DMSO/Rhodamine 6G solution was added.
- The microsphere solution was placed in a freezer at -20°C for 24 hours and then removed and allowed to thaw for 24 hours.
- Repeat this freeze-thaw cycle three times.
Preparation of Microspheres:
- New calculations for the amount of DMSO/Rhodamine 6G to be added:
For a 90:10 ratio:
For a 50:50 ratio:
- Information about prepared microspheres:
|Prepared Clay-PVA(MW 146,000-186,000) microspheres
| Composition of hydrogel(ratio of PVA to clay)
||Amount of PVA added(g)
||Amount of clay added(g)
||Concencentration of DMSO/dye stock solution added(μM)
||Amount of DMSO/dye added(mL)
| 90:10 PVA:110% NaMT
| 50:50 PVA:110% NaMT
| 90:10 PVA:110% Lamponite
- After the addition of dye/DMSO to the 110% Lamponite, the dye appeared to stick to very small spheres at the bottom of the beaker. Bright pink spheres immediately formed. This did not occur for the samples containing 110% NaMT.