# User:Tamanika Tinsley/Notebook/Chem 581 Biomaterials Design Lab/2014/09/12

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## Sept 12 - Exfoliated Clay

• Group Members Andrew Farag Sr (Undergrad) and Michael Bible Jr (Undergrad)
• Group Name : AMT

## Objective

Start preparing new films using exfoliated clay. Perform XRD measurement. Continue analysis of DSC and UVVis.

## Description

1. Exfoliated Clays
1. An exfoliated clay has had all of its layers separated from one another. Instead of having layers in water, you have single sheets of material. This should change the absorption properties of the clay. We are going to test PVA-exfoliated clay materials against the regular PVA-clay material.
2. To exfoliate clay, you stir it in water for 24 hours. (Luckily Dr. Fox has done this for us already).
3. Stock solution 4% sodium montmorillonite
1. Determine how to make a film such that you make a 10% clay (1g of PVA, ?? of exfoliated clay solution).
4. Prepare a crosslinked film with the exfoliated clay in a similar manner to your other films
2. Powder Xray diffraction
1. We will discuss X-ray diffraction
2. You will dry and set up your samples for use in the xrd instrument.
3. I will show everyone how to use the instrument
3. Continue DSC analysis
4. Continue UVVis Analysis
1. We all need to have a discussion about what our possible sources of error are.
2. We may need to set up new malachite green/PVA-film experiment (just the PVA, not PVA clay at this point)

(Description from Dr. Hartings lab notebook Dr. Hartings)

## Calculations

A 10% clay has 1g of PVA and should have .11g of exfoliated clay.

.11g of clay = (4% solution)x = (0.04)x

x = 2.75g of exfoliated clay solution

Actual mass of solution used was 2.5387g.

Figure 1. Shows the calculations for the mass of water in the films.

## Notes

New Malachite Green/PVA-Film Experiment

After the last experiment in which PVA-films with and without clay were placed in solutions of malachite green with various concentrations, it was noticed that some of the malachite green was absorbed by the glass vials in which the experiment was performed. Therefore an additional experiment was set up with the varying concentrations of MG in the glass vials only, no films were added, so that a calculation can be made of how much MG is absorbed into the glass vials.

• We set up our new MG/PVA-film experiment as follows
• Pieces of PVA-only films were massed and placed in vials containing solutions of different concentrations of malachite green.
• Additionally, our group placed just solutions of 80ppm MG and 8ppm MG in two vials to see how much MG would be absorbed by the glass.
• The masses of the films and vials used can be found below:

## Analysis of Differential Scanning Calorimetry Data

The following figures show the Differential Scanning Results for the PVA with clay at different concentrations of malachite green.(See Figures 1-5)

Figure 1. PVA with Clay

Figure 2. Clay at 2ppm

Figure 3. Clay at 8ppm

Figure 4. Clay at 80ppm

Figure 5. Clay at 200ppm

The following figures show the Differential Scanning Results for the PVA at different concentrations of malachite green.(See Figures 6-10)

Figure 6. PVA

Figure 7. PVA at 2ppm

Figure 8. PVA at 8ppm

Figure 9. PVA at 80ppm

Figure 10. PVA at 200ppm