Tasks for 5 September 2014
- Continuation from Dr. Hartings procedure
- Calibration curves for malachite green absorbance were made using UV-Vis spectrometry. The ultimate purpose is to determine the equilibrium of the malachite green dye against bound MG.
- New film synthesis was undertaken and film synthesis from Sept. 3 2014 was completed.
New Film synthesis
- 1.0050 g of 22,000MW PVA was used to make the polymer film
- 1.0004 g of PVA and 0.1077 g of sodium montmorillonite were used to make the 10% w/w polymer-clay film
UV-Vis analysis of MG leftover solutions
- Dilutions of some of the MG solutions were made in order to be able to use the spectrometer
- Diluted 200 ppm 100 times by adding 100μL to a 10 mL volumetric flask. This was done for both the polymer and polymer-clay in 200 ppm MG.
- Also diluted 80 ppm 50 times by adding 200μL to a 10 mL volumetric flask. Done for both polymer and polymer-clay solutions.
- Ran standards of MG solutions (0.2, 0.5, 1.1, 1.4, 1.7 and 2.0 ppm) in order to make calibration curves.
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From this, it can be seen that there are two major peaks at 425 nm and 615 nm.
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These calibrations curves show that the molar absorptivity at 425 nm is 0.0266 M-1cm-1 and 0.1293 M-1 cm-1 at 615 nm.
- Ran UV-Vis on solutions left over after removing films from solution, to figure out the amount of dye not absorbed by films.
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Using Beer-Lambert's Law, the concentrations of leftover dye in solution were calculated:
- At 425 nm,
- PVA 2 ppm = 0.112 ppm
- PVA 8 ppm = 0.639 ppm
- PVA in diluted 80 ppm = 0.752. After accounting for dilution = 37.6 ppm
- PVA in diluted 200 ppm = 0.714. After accounting for dilution = 71.4 ppm
- PVA-clay 2 ppm = 0.112 ppm
- PVA-clay 8 ppm = 0.226 ppm
- PVA-Clay in diluted 80 ppm = 0.112. After accounting for dilution = 5.6 ppm
- PVA-Clay in diluted 200 ppm = 0.188. After accounting for dilution = 18.8 ppm
- At 615 nm,
- PVA 2 ppm = 0.0696 ppm
- PVA 8 ppm = 0.495 ppm
- PVA in diluted 80 ppm =0.727. After accounting for dilution = 36.3 ppm
- PVA in diluted 200 ppm = 0.712. After accounting for dilution = 71.2 ppm
- PVA-clay 2 ppm = 0.031 ppm
- PVA-clay 8 ppm = 0.093 ppm
- PVA-Clay in diluted 80 ppm = 0.077. After accounting for dilution = 3.9 ppm
- PVA-Clay in diluted 200 ppm = 0.147. After accounting for dilution = 14.7 ppm
Determining the amount of MG dye absorbed per mg of film
Note, the results were calculated using 615 nm values
- PVA film in 2 ppm MG
- 2 ppm - 0.0696 = 1.9304 ppm of MG absorbed
- (1.9304 mg MG)/(L solution) × 0.010 L solution = 0.0193 mg MG/film
- Since the clay film weighed 0.1286 g, the amount of MG dye absorbed in the polymer film into 2 ppm MG green solution is (0.0193 mg MG)/(0.1286)=0.00015 mg MG/mg polymer film.
- PVA film in 8 ppm MG
- PVA film in 80 ppm MG
- PVA film in 200 ppm MG
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- PVA-Clay film in 2 ppm MG
- 0.00029 mg MG/mg PVA-Clay film
- PVA-Clay film in 8 ppm MG
- 0.0012 mg MG/mg PVA-Clay film
- PVA-Clay film in 80 ppm MG
- 0.0099 mg MG/mg PVA-Clay film
- PVA-Clay film in 200 ppm MG
- 0.0177 mg MG/mg PVA-Clay film
FTIR Analysis of Films with MG dye
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