Objectives
- Run diffusion testing on microspheres with dye added 2013/03/20. These microspheres were prepared on 2013/02/20.
- Run DSC of microsphere samples prepared on 2013/03/22
- Decant microsphere samples prepared on 2013/03/29
Decanting
The general protocol described on 2013/03/01 was followed.
- It was found that the organic safflower oil layer needed to be removed several times. After removing a layer of safflower oil, the microspheres were allowed to sit for 15 minutes, and more oil was then able to be removed.
- Due to the presence of what appeared to be small particles in the safflower oil, the safflower oil layer that was removed from the samples was saved, labeled and parafilmed. The safflower oil layer will be vacuum filtered and obtained solids will be tested using DSC in order to see if there is a difference between the larger spheres that formed at the bottom of the vial and the smaller particles suspended in the safflower oil layer.
DSC
- Please refer to Karlena Brown's laboratory notebook 2013/04/03 for any information concerning DSC sample preparation.
Diffusion Testing
A new general protocol for the preparation of was used for the diffusion testing of the prepared microspheres. It was determined that the previous protocol did not allow for a quantitative understanding of the amount of dye diffused from the samples.
General Protocol:
- The microspheres were removed from their respective vial and placed in new, clean 20mL vials.
- 15mL of deionized H2O were added to each vial.
- A timer was started, and every 15 minutes, a sample of distilled H2O was removed from the beaker and placed in an unfrosted cuvette.
- After running the sample on the fluorimeter, the sample was readded to the diffusion vial.
- This process was repeated for 2 hours.
General information on the parameters of the fluorescence run:
- Starting wavelength: 500nm
- End wavelength: 650nm
- Excitation wavelength: 526nm
- Exitation slit: 10
- Emission slit: 10
- Scan rate/Speed: 1200
Spectra
Figure 1. Diffusion Testing of Rhodamine 6G in microspheres prepared with 90:10 ratio of PVA MW 146,000-186,000: 50% CEC NaMT
- Fluorescence intensity maximum is 6.985.
Figure 2. Diffusion Testing of Rhodamine 6G in microspheres prepared with 90:10 ratio of PVA MW 146,000-186,000: 110% Laponite
- Fluorescence intensity maximum is 5.109.
Figure 3. Diffusion Testing of Rhodamine 6G in microspheres prepared with a 90:10 ratio PVA 146,000-186,000: NaMT
- Fluorescence intensity maximum is 26.734
Figure 4. Diffusion Testing of Rhodamine 6G in microspheres prepared with a 50:50 ratio PVA 146,000-186,000: NaMT
- Fluorescence intensity maximum is
Figure 5. Diffusion Testing of Rhodamine 6G in microspheres prepared with a 50:50 ratio PVA 146,000-186,000: 50% CEC NaMT
- Fluorescence intensity maximum is 11.661
Figure 6. Diffusion Testing of Rhodamine 6G in microspheres prepared with a 50:50 ratio PVA 146,000-186,000: 110% CEC Laponite
- Fluorescence intensity maximum is 137.319.
Notes
- A tested "microspheres" more closely resemble smaller, more circular, more flexible hydrogels. Other microsphere samples were prepared and may more closely resemble microspheres.
- The microsphere prepared with a 50:50 ratio PVA 146,000-186,000: 110% CEC Laponite caused the most diffusion of dye. All microspheres will be used for pressure testing, however, because not all dye leaked out.
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