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How to make the gel

This version was saved 15 years ago View current version     Page history
Saved by Nancie Ravenel
on March 24, 2009 at 8:05:39 pm
 

    

The information page from Noveon includes information on relative base strength parts per 1 part Pemulen.


The master recipe Shelburne has used for the gel is

100 mL de-ionized water

10mL  base

1 g. Pemulen TR2


At Shelburne, we have used two alkaline compounds to make up the gel: triethanolamine (TEA) and a solution of 2% Tris(hydroxymethyl)aminomethane (TRIS) in deionized water.  Making the gel up with TEA using this recipe results in a gel with a pH of about 7.5-8, but measure the pH to make sure.

 

When this gel proves to produce an emulsion that is too aggressive for cleaning, the gel recipe is modified replacing some of the TEA with the solution of 2% TRIS, a weaker base than TEA.  This often results in a less aggressive emulsion cleaner even though the pH remains at 7.5-8.

 

The first step in preparing the gel is to mix the water and the base together.  Then Pemulen powder is added slowly with constant stirring.  While we initially had used a magnetic stirrer to create the gel, Laura Brill found that stirring the Pemulen powder into the water by hand using a miniature balloon wisk created a smoother gel from the beginning.  

 

We have found that the pH of the gel will shift over time, so if you store the gel, make sure you measure the pH before using it.

 

 

 

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