# User:Michael S. Bible/Notebook/581/2014/09/17

Biomaterials Design Lab Main project page
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## Today's Agenda

• Measure MG new data through UV-Vis
• Film Processing
• Filter stirring clay in centrifuge
• 4000rpm for 30 minutes at 4°C for original separation
• rinse with water then ethanol for 10 minutes
• repeat for another cycle and drying done by Dr. Hartings

Tami centrifuged the organic cation-exchanged clay solution that we started synthesizing on September 10th

## PXRD

• Set up PXRD of PVA+Clay films at different concentrations.
• Tray 1 -Clay powder-control
• Tray 2 -8ppm prepared by Madeleine's group
• Tray 3 -2ppm prepared by Jake's group
• Tray 4 -PVA film-control
• Tray 5 -80ppm prepared by Eleni's group
• Tray 6 -200ppm prepared by our group
• Instrument Settings
• 2o start angle
• 40o stop angle
• 1o/second scan speed (this seems too fast, will check on this)
• 0.5o sampling width

## Calculations

• Dilutions of MG solutions
• 200ppm*0.2mL=8ppm*5mL(vial with PVA film)
• 80ppm*0.5mL=8ppm*5mL(vial with no film)
• 80ppm*0.2mL=8ppm*2mL(vial with PVA film)

## Figures

Figure 1. Shows the separation of the clay after the first washing of water.

Figure 2. Shows the dried clay being collected for future testing.

## Results

UV-Vis was performed on the solutions of MG started on September 12 and the results can be found in the graph and chart below.

The concentration of MG in the film was calculated in the following way:

(Initial ppm)(.010L) = (Initial mass of MG in 10 mL of solution, mg)

[(Solution Absorbance post-experiment)/(molar abosorptivity of Malachite Green according to calibration curve from September 3rd = 0.1193/ppm)]x(Volume = 0.01L) = (Final mass of MG in solution, mg)

[(Initial mass of MG in Solution)-(Final mass of MG in solution, mg)]/(initial mass of film) = (Concentration of MG in film, mgMG/gFilm)

## Notes

Exfoliated Clay Film During the second phase of film synthesis today,a beaker of heating Sodium Sulfate was spilled in the hood and shorted the electricity. As a result, the following differences in protocol occurred today:

• The sodium sulfate solution was kept at room temperature with no stirring
• When transferred to HCl solution, the temperature fluctuated between 75°C and 90°C with stirring
• Sodium bicarbonate solution was not stirred