# User:Andrew K Farag/Notebook/CHEM-581/2014/09/10

Biomaterials Design Lab Main project page
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## Objective

Finish film preparation and begin preparation of ionic liquid modified clays.

## Description

We are going to exchange the sodium in the sodium montmorillonite for an organic cation. The procedures are taken from these two sources (1, 2 along with Karlena Brown's thesis. We are working from the starting point that there are 92 miliequivalents (meq) of Na+ per 100g of montmorillonite.

1. Add 1.1g of Sodium Montmorillonite (NaMT) to a scintillation vial containing 20mL of 50:50 HPLC grade water:ethanol.
2. Determine the amount of cation to add if using either tributylhexadecylphosphonium bromide or (1-hexadecyl)triphenylphosphonium bromide to exchange 100% of the Na from the clay.
3. Add this amount of phosphonium ion to the clay solution.
4. Cap the vial
5. Stir for 1 week.
1. Centrifuge
2. Dry in oven at 90C overnight
3. Grind with a mortar and pestle.
4. Store in a dessicator

Here's an excellent paper on good graphing procedures.

## Data

1. To begin, we added 20 mL of a 50:50 HPLC grade water:ethanol solution to a scintillation vial.
2. To this, we added 1.1488g of NaMT.
4. The vial was then capped and stirring was begun with the intention to stir the solution for a week.

## Calculations

We wanted to exchange 100% of the Na+ from the clay so we needed to add an equivalent number of moles of tributylhexadecylphosphonium bromide to our NaMT.

• We started with 1.1488g of NaMT which has 1.05x10-3 equivalents of Na+.
• (1.1488g NaMT)x[(92 meq Na+)/(100g NaMT)]=1.05 milliequivalents of Na+
• Tributylhexadecylphosphonium bromide has a molecular weight of 507.65g/mol.
• Thus we determined that we needed 0.533g of Tributylhexadecylphosphonium bromide by the following calculation:
• (1.05x10-3mols Tbhp bromide)x[(507g Tbhp bromide)/(1 mol Tbhp bromide)] = 0.533g Tributylhexadecylphosphonium bromide.
• Note, however, the actual mass of Tributylhexadecylphosphonium bromide used was 0.5349g.

## Notes

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