User:Moira M. Esson/Notebook/CHEM-581/2013/02/13

Objectives

1. Determine the lower and upper limit of detection of Rhodamine 6G on the fluorimeter.
2. Run fluoroscopy of all hydrogel samples that were placed in distilled H₂O to soak on 2013/02/06.
3. Run diffusion test on prepared microspheres(PVOH 146K MW and Lamponite clay in a 90:10 ratio) with Rhodamine 6G dye added.

Notes

• The microspheres prepared on 2013/02/08 did not form microsphere structures. After placing on the lyophilizer for over 48 hours, a large, solid clump of pure white material formed. This indicates that the emulsion that was prepared was not sufficient for the precipitaiton of microsphere structures. A mortar and pestle was used to grind the large PVOH and clay solid in an attempt to create microsphere structures. DSC will be run of these structures.
• The two hydrogels prepared on 2013/02/08 were removed from the freezer to thaw for their last freeze-thaw cycle. During the next lab session, these hydrogels will be placed in distilled H₂O to soak.
• After observation of the hydrogels that were allowed to soak in Rhodamine 6G 1μM solution, it was apparent that the concentration of Rhodamine 6G was enough in the gel. A small, second fraction of 3mL of 1μM Rhodamine 6G was added to the hydrogels. The hydrogels will be allowed to soak until 02/15/13, when diffusion tests will be run on the samples.
• Due to the lack of success with the preparation of PVOH/clay microspheres, a new method for the preparation of microspheres will be used. An aqueous solution of PVOH/clay will be suspended in mineral oil with the necessary amount of DMSO additive. This will be suspended and emulsified for approximately 20 minutes at 90°C. The prepared microspheres will then undergo the freeze thaw method utilized by the hydrogels.

Fluorescence