User:James C. Schwabacher/Notebook/CHEM-571/2014/10/31: Difference between revisions

From OpenWetWare
Jump to navigationJump to search
(Autocreate 2014/10/31 Entry for User:James_C._Schwabacher/Notebook/CHEM-571)
 
No edit summary
Line 6: Line 6:
| colspan="2"|
| colspan="2"|
<!-- ##### 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. ##### -->
==Objective==
To continue to find a usable PVA-NaMT bead synthesis method.


Notes below were recorded in [[User:Mary_Mendoza/Notebook/CHEM_581:_Experimental_Chemistry_I/2014/10/31| Mary's Notebook]]


==Continuation of Bead Synthesis Trials==
* The burette set-up utilized by Eleni, Melvin, and Becca's group will be used; details of their assembly can be found on Kalivas' entry for [[User:Eleni N. Kalivas/Notebook/CHEM-571/2014/10/29|10/29/2014]].
* The assembly was prepared as shown in the picture.
[[Image:IMG 3226.JPG|thumb|center|600x600px]]


==Description==
# A column was set up with glutaraldehyde and hexane. Air is being bubbled through the column to mix the two liquids.
# PVA-Clay will be dropped down the column


==Objective==
<u>Hexane Trial</u>
Learn how to maintain an OpenWetWare Notebook.
* The PVA-Clay formed beads within the hexane and floated down the column. They did not cross-link fast enough if at all and they dissolved into the glutaraldehyde.
 
==Description==
# Add experimental record here. Include what, how, and why...


==Data==
<u>Organic-Glutaraldehyde Solution</u>
* Add data and results here...
* We attempted to add acetone to glutaraldehyde and then add hexane to get rid of the solvent layers. The solution was not hydrophobic enough to form beads however. When only a slight layer of hexane and stirring were applied, it yielded no good results.


==Notes==
# We have decided to abandon the beads and begin synthesis of ribbons
This area is for any observations or conclusions that you would like to note.
## We filled a column with acetone and 1.5mL of Glutaraldehyde
## we then dropped in the PVA-Clay


==Trial of Several Organic Solvents==
* ''I observed that as soon as the organic phase, formed bead comes into contact with the aqueous phase of the glutaraldehyde, the bead disperses into the aqueous solution. I decided to conduct my own trials and have my group members continue the burette-ribbon experiments.''
* ''I concluded that the dilemma in the formation of beads is the immiscibility of the organic phase which forms the beads and the aqueous phase that cross-links the beads.''
* ''Therefore, I thought, I can resolve this issue by choosing several organic solvents slightly miscible with water but hydrophobic enough to form the beads.''
* ''In an attempt to keep the reaction mixture homogenized, motion is required. Thus, the reaction should be kept stirring on a stir plate. Also, stirring prevents the formed beads from clumping together."


Use categories like tags. Change the "Course" category to the one corresponding to your course. The "Miscellaneous" tag can be used for particular experiments, as instructed by your professor. Please be sure to change or delete this tag as required so that the categories remain well organized.
* I used the solvent miscibility table provided by Dr. Hartings taken from chemical company, phenomenex, as shown in the picture.
[[Image:Solvent miscibility chart.jpg|thumb|center|494x599px]]


[[Category:Course]]
<u>Acetonitrile Trial</u>
[[Category:Miscellaneous]]
* A drop of the PVA-clay was added into 3 mL of acetonitrile contained in a 12x100 mm, 8 mL disposable test tube.
* The PVA-clay did not form beads.
* Acetonitrile was tested without the use of the solvent miscibility chart. Upon checking the chart, the solubility in water of acetonitrile (%w/w) is 100.


<u>DMSO and Ethyl Acetate</u>


* Hence, I selected the top 5 least immiscible organic solvent according to their solubility in water (%w/w) as shown in the picture.
* I first tested dimethyl sulfoxide (DMSO) and ethyl acetate. For DMSO, a quick formation of bead was observed but readily dispersed as it settled on the bottom of the tube. On the other hand, as the drop of PVA-clay-HCl passed through the ethyl acetate, the bead retained its shape for at least 5 to 7 seconds and gradually dispersed.
* Without testing the remaining organic solvents, I chose ethyl acetate as my organic solvent. It had the suitable features such that it enables the bead formation and its slight immiscibility with water.


[[Category:Course]]
* Next, it was time to test ethyl acetate with glutaraldehyde. The following amounts for the ethyl acetate trial were not exactly measured but made by approximation. I took a 50 mL beaker with a magnetic stir bar. I approximately added 15-20 mL of ethyl acetate. In a drop wise manner, I added my PVA-clay-HCl solution using a pasteur pipette. I added at least 500 uL of glutaraldehyde.
[[Category:Miscellaneous]]
* With this experimental set-up, I was able to form beads but had to resolve the ratio of materials I used since everything was performed by approximation.


[[Image:Solvents.png|center]]




Revision as of 13:28, 14 December 2014

Biomaterials Design Lab <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>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</html>Next entry<html><img src="/images/5/5c/Resultset_next.png" border="0" /></html>

Objective

To continue to find a usable PVA-NaMT bead synthesis method.

Notes below were recorded in Mary's Notebook

Continuation of Bead Synthesis Trials

  • The burette set-up utilized by Eleni, Melvin, and Becca's group will be used; details of their assembly can be found on Kalivas' entry for 10/29/2014.
  • The assembly was prepared as shown in the picture.

Description

  1. A column was set up with glutaraldehyde and hexane. Air is being bubbled through the column to mix the two liquids.
  2. PVA-Clay will be dropped down the column

Hexane Trial

  • The PVA-Clay formed beads within the hexane and floated down the column. They did not cross-link fast enough if at all and they dissolved into the glutaraldehyde.

Organic-Glutaraldehyde Solution

  • We attempted to add acetone to glutaraldehyde and then add hexane to get rid of the solvent layers. The solution was not hydrophobic enough to form beads however. When only a slight layer of hexane and stirring were applied, it yielded no good results.
  1. We have decided to abandon the beads and begin synthesis of ribbons
    1. We filled a column with acetone and 1.5mL of Glutaraldehyde
    2. we then dropped in the PVA-Clay

Trial of Several Organic Solvents

  • I observed that as soon as the organic phase, formed bead comes into contact with the aqueous phase of the glutaraldehyde, the bead disperses into the aqueous solution. I decided to conduct my own trials and have my group members continue the burette-ribbon experiments.
  • I concluded that the dilemma in the formation of beads is the immiscibility of the organic phase which forms the beads and the aqueous phase that cross-links the beads.
  • Therefore, I thought, I can resolve this issue by choosing several organic solvents slightly miscible with water but hydrophobic enough to form the beads.
  • In an attempt to keep the reaction mixture homogenized, motion is required. Thus, the reaction should be kept stirring on a stir plate. Also, stirring prevents the formed beads from clumping together."
  • I used the solvent miscibility table provided by Dr. Hartings taken from chemical company, phenomenex, as shown in the picture.

Acetonitrile Trial

  • A drop of the PVA-clay was added into 3 mL of acetonitrile contained in a 12x100 mm, 8 mL disposable test tube.
  • The PVA-clay did not form beads.
  • Acetonitrile was tested without the use of the solvent miscibility chart. Upon checking the chart, the solubility in water of acetonitrile (%w/w) is 100.

DMSO and Ethyl Acetate

  • Hence, I selected the top 5 least immiscible organic solvent according to their solubility in water (%w/w) as shown in the picture.
  • I first tested dimethyl sulfoxide (DMSO) and ethyl acetate. For DMSO, a quick formation of bead was observed but readily dispersed as it settled on the bottom of the tube. On the other hand, as the drop of PVA-clay-HCl passed through the ethyl acetate, the bead retained its shape for at least 5 to 7 seconds and gradually dispersed.
  • Without testing the remaining organic solvents, I chose ethyl acetate as my organic solvent. It had the suitable features such that it enables the bead formation and its slight immiscibility with water.
  • Next, it was time to test ethyl acetate with glutaraldehyde. The following amounts for the ethyl acetate trial were not exactly measured but made by approximation. I took a 50 mL beaker with a magnetic stir bar. I approximately added 15-20 mL of ethyl acetate. In a drop wise manner, I added my PVA-clay-HCl solution using a pasteur pipette. I added at least 500 uL of glutaraldehyde.
  • With this experimental set-up, I was able to form beads but had to resolve the ratio of materials I used since everything was performed by approximation.



Retrieved from "https://openwetware.org/mediawiki/index.php?title=User:James_C._Schwabacher/Notebook/CHEM-571/2014/10/31&oldid=848047"