User:Moira M. Esson/Notebook/CHEM-581/2013/03/27

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Objectives

  • Decant all microsphere samples prepared on 2013/03/20 and 2013/03/22
  • Rinse microsphere samples with hexanes and allow samples to completely dry.


Microsphere Work-Up

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.


Rinsing with hexanes:

  • Although the previous method for microsphere work-up included the vacuum filtration of the microspheres with a hexane rinse described on 2013/03/08, this step was unnecessary. The prepared microspheres were incredibly small in size, making a rinse in hexanes sufficient enough for the removal of all mineral oil. Similarly, due to the small size of the spheres difficulties arose in finding filter paper with a small enough pore size to ensure the retention of the spheres.


General Protocol:

  1. After the removal of the safflower oil organic layer from the sample container, ~3mL of hexanes were added to each vial.
  2. The samples were stirred and allowed to sit for ~3minutes.
  3. Using a pasteur pipette, the hexanes were removed from the vial and discarded in the appropriate waste container.
  4. Repeat 1-3 twice.
  5. The samples remained in the fume hood over night without a cap to ensure complete removal of all hexanes.


Notes

  • A set of control microspheres will be prepared next time with only PVA MW:130,000 and PVA MW 146,000-186,000. These will be prepared on a 0.05g scale
  • A set control hydrogels will be prepared next time with only PVA MW 130,000 and PVA MW 146,000-186,000. These will be prepared on a 1g scale.
  • DSC will be run on all microsphere samples decanted and rinsed today.
  • X-ray diffraction will be run on all prepared microsphere samples in order to determine whether clay has agglomerated separately from the PVA. As a hydrophilic polymer, clay blends well and a peak shift below 10 degrees is a strong indicator of intercalation.



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