User:Moira M. Esson/Notebook/CHEM-581/2013/02/06: Difference between revisions
From OpenWetWare
(9 intermediate revisions by the same user not shown) | |||
Line 7: | Line 7: | ||
<!-- ##### DO NOT edit above this line unless you know what you are doing. ##### --> | <!-- ##### DO NOT edit above this line unless you know what you are doing. ##### --> | ||
==Objectives== | ==Objectives== | ||
# Prepare PVA(MW 130,000) microspheres through suspension cross-linking of a polymeric solution with glutaraldehyde. | |||
# Remove prepared MW 130,000 PVA hydrogels from freezer and begin soaking in water. | |||
# Finish preparing PVA(MW 130,000) hydrogels for freeze-thaw method. | |||
# Filter prepared clay exchanges. | |||
# Prepared DSC samples of all used clays. | |||
==PVA Microspheres== | ==PVA Microspheres== | ||
'''General Protocol''': | '''General Protocol''': | ||
*Reaction should be carried out using a reflux condenser and a thermostatic water bath of | *Reaction should be carried out using a reflux condenser and a thermostatic water bath of 55°C. | ||
# Dissolve 1g total of PVA and clay additive in 5mL hot,deionized water. | # Dissolve 1g total of PVA and clay additive in 5mL hot,deionized water. | ||
# Acidify the solution using 0.25mL 0.5M H<sub>2</sub>SO<sub>4</sub>. | # Acidify the solution using 0.25mL 0.5M H<sub>2</sub>SO<sub>4</sub>. | ||
# Dissolve 0.6g Cellulose acetate butyrate in 25mL 1,2-dichloroethane. | # Dissolve 0.6g Cellulose acetate butyrate(CAB) in 25mL 1,2-dichloroethane. | ||
# Pour the acidified PVA solution into the 25mL 1,2-dichloroethane solution. | # Pour the acidified PVA solution into the 25mL 1,2-dichloroethane solution. Place all in a clean round bottom(RB) flask. | ||
# Stir the water/1,2-dichlorethane solution for 30 minutes. | # Stir the water/1,2-dichlorethane solution for 30 minutes. | ||
# After 30 minutes stirring, add 0.75mL glutaraldehyde to the solution. | # After 30 minutes stirring, add 0.75mL glutaraldehyde(GA) to the solution. | ||
# After the addition of glutaraldehyde, allow the reaction to carry out for 3 additional hours at | # After the addition of glutaraldehyde, allow the reaction to carry out for 3 additional hours at 55°C. | ||
# Filter the produced microspheres from the solution using a a sintered glass filter and a vacuum. | # Filter the produced microspheres from the solution using a a sintered glass filter and a vacuum. | ||
# Wash the collected microspheres using the following solvents in the following order: | # Wash the collected microspheres using the following solvents in the following order: | ||
Line 26: | Line 30: | ||
##cold water | ##cold water | ||
##methanol | ##methanol | ||
# | # Scrap all collected microspheres into a small vial. | ||
# Freeze microspheres in liquid nitrogen for ~2 minutes. | |||
# Place on [ask Dr. Hartings name of machine again] overnight to completely dry. | |||
*The following procedure was adapted from the article Poly(vinyl alcohol) microspheres with pH- and thermosensitive properties as temperature-controlled drug delivery [http://www.sciencedirect.com/science/article/pii/S1742706110002151] | *The following procedure was adapted from the article Poly(vinyl alcohol) microspheres with pH- and thermosensitive properties as temperature-controlled drug delivery [http://www.sciencedirect.com/science/article/pii/S1742706110002151] | ||
<br> | <br> | ||
Line 35: | Line 41: | ||
# 1,2-dichloroethane should be kept in the flammable storage safety cabinet when not in use. | # 1,2-dichloroethane should be kept in the flammable storage safety cabinet when not in use. | ||
# When in use, 1,2-dichloroethane should be kept in the fume hood. | # When in use, 1,2-dichloroethane should be kept in the fume hood. | ||
<br> | |||
PVA Microsphere information: | |||
{| {{table}} | |||
| align="center" style="background:#f0f0f0;"|'''Preparation of Microspheres using PVA MW 146,000-186,000''' | |||
| align="center" style="background:#f0f0f0;"|'''''' | |||
|- | |||
| Amount of PVA added(g)||0.9001 | |||
|- | |||
| Amount of Lamponite clay added(g)||0.1004 | |||
|- | |||
| Amount of cellulose acetate butyrate added(g)||0.6066 | |||
|- | |||
| Amount of GA added(mL)||0.75 | |||
|- | |||
| Amount of H2SO4 added(mL)||0.25 | |||
|} | |||
<br> | |||
Observations: | |||
*The dispersion agent(hereout referred to as CAB), lamponite clay and PVA formed a sort of suspension in the water/organic solvent solution. It did not appear to fully dissolve. Used a spatula to scrape the side of the RB flask in order to try and break up the large chunks. | |||
* After addition to heat, the large chunks generally broke apart. Small spheres seemed to be forming after approximately an hour spinning. | |||
*After 3 hour spinning and heat, large clumps of spheres formed. Upon scraping with a spatula these clumps broke apart into what appeared to be smaller spheres. | |||
*Large clumps indicates that we may want to change portion of our method to produce smaller microspheres. | |||
*The spheres were a cloudy, white color throughout. | |||
==Hydrogel Preparation== | |||
* The general protocol described on January 30th was followed. | |||
* | |||
<br> | |||
==Clay Filtration== | |||
Revision as of 12:39, 6 February 2013
Project name | <html><img src="/images/9/94/Report.png" border="0" /></html> Main project page <html><img src="/images/c/c3/Resultset_previous.png" border="0" /></html>Previous entry<html> </html>Next entry<html><img src="/images/5/5c/Resultset_next.png" border="0" /></html> | ||||||||||||
Objectives
PVA MicrospheresGeneral Protocol:
Hydrogel Preparation
Clay Filtration |