FTIR

 

Materials

KBr - 99+% purity, IR grade, store with desiccant

agate mortar and pestle

PLLA, PLGA

Carver Press mold (stored in desiccant, GRBrown E207)

Carver Press machine (GRBrown E207)

FTIR (GRBrown E204)

Analytical scale

Spatula

Acetone

 

 

Safety

1.     Wear disposable latex gloves at all times

2.     Wear safety glasses at all times.

 

 

Sample Grinding

NOTE:  Sample grinding should be done in the undergraduate lab.

Samples of PLGA, PLLA, and a reference blank need to be prepared.

1.     Weigh 100-150 mg KBr. Add to mortar.

2.     Weigh 2-3 mg sample.  (Sample should be 2-3 wt% in KBr.)  Add to mortar.

3.     Grind them to make a fine power with the pestle.  This should take a minimum of 2-3 minutes.

4.     Transfer KBr/sample from mortar to weighing paper.

5.     Follow Clean-Up, Step 1 below before preparing another sample.

 

 

Load Sample into Carver Press Mold

NOTE:  Sample loading should be done in GRBrown E207 under supervision of a T.A.

1.     Place the base on a flat surface and insert the o-ring in the groove.

2.     Place the die assembly over the post in the base.

3.     Insert the anvil (small metal cylinder) polished side up (ringed side down) into the center hole of the die.

 

 

 

 

 

 

 

 

 

4.     Transfer KBr/sample from weighing paper to the center hole in the mold and onto the anvil.

5.     Level the sample materials using spatula and gentle shaking.

6.     Place the second o-ring in the groove.

7.     Place the black barrel on the top.

8.     Insert the metal plunger polished side down.

 

 

Pressing the Pellet Disk

NOTE:  These experiments should be done under the direct supervision of a T.A.  The T.A. will operate the Carver Press.

1.     Place the complete die in a hydraulic Carver press machine.

2.     Press the pellet disk.

3.     Release the pressure after 2 minutes.

4.     Wait another minute before removing the die from the press.

5.     Rotate the assembly upside down and insert the die in the press.

6.     Place the extractor over the aperture for ejection of the pellet.

7.     Pump the pressure.

8.     As soon as the anvil clears the well, slow the pumping rate down.

9.     Carefully remove disk from mold.

NOTE:  If the pellet disk is not smooth or transparent, you will need to repeat the process above.  Lower the wt% polymer in the sample in an effort to produce a transparent disk.

 

 

Operation of FTIR

NOTE:  These experiments should be done under the direct supervision of a T.A.  The T.A. will operate the FTIR and corresponding computer.

1.     Start up FTIR and associated software.

2.     Load pellet disk into sample chamber.  Secure with clips. 

3.     Load sample chamber into FTIR with handle at base.  Confirm that you can see laser light through the sample.

4.     Run FTIR scan on background sample.

5.     Run FTIR scans on test samples.

6.     Print out all results.

7.     Identify peaks using reference materials in library.

 

 

Clean-Up

1.     Clean mortar, pestle and mold with acetone.  Then, rinse each component with water and allow to air dry.

2.     All FTIR mold pieces should be stored with desiccant.

3.     Pellet disks can be disposed of in regular garbage.