User:Alicia Rasines Mazo/Notebook/CHEM-581 Experimental Chemistry I/2014/09/05

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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.

Image:MG spectrum 050914.png
From this, it can be seen that there are two major peaks at 425 nm and 615 nm. Image:MG calibration 050914.png
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.

Image:Absorbance of MG without PVA fil 050914.png Image:Absorbance of MG post removal of polymer film.png
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
    • 0.0013 mg MG/mg PVA film
  • PVA film in 80 ppm MG
    • 0.0049 mg MG/mg PVA film
  • PVA film in 200 ppm MG
    • 0.0121 mg MG/mg PVA film


  • 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

Image:FTIR 2 050914.jpeg

Image:FTIR 1 050914.png


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