User:Mary Mendoza/Notebook/CHEM 581: Experimental Chemistry I/2014/09/17

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Collection of DSC data

  • Jacob Esenther extracted the DSC data from the Qseries interface, TA Universal Analysis. The data was compiled in a table below:
PVA Conc. (ppm) ' Energy (J/g) H₂0 (mg) Glass Transition (⁰C) Water Evaporation Peak (⁰C)
2 928.4 1.3239 69.11 and 79.8 108.58
8 1001 1.9796 68.77 99.31
80 1340 2.9384 68.338 105.91
200 819.4 1.0803 68.63 128.77
Control 582.9 0.95407 68.566 125.61
PVA-Clay 2 1303 1.8931 68.716 100.97
8 883.8 1.4585 68.644 99.59
80 861.3 2.2633 68.866 102.05, 106.55, and 128.44
200 N/A N/A N/A N/A
Control 671.2 0.90296 69.164 116.15 and 105.16
  • James Schwabacher prepared the following graphs from the DSC:
Polyvinyl Alcohol Film
Polyvinyl Alcohol Film in 2 ppm malachite green
Polyvinyl Alcohol Film in 8 ppm malachite green
Polyvinyl Alcohol Film in 80 ppm malachite green
Polyvinyl Alcohol Film in 200 ppm malachite green
PVA-sodium montmorillonite film
PVA-sodium montmorillonite film in 2 ppm malachite green
PVA-sodium montmorillonite film in 8 ppm malachite green
PVA-sodium montmorillonite film in 80 ppm malachite green
PVA-sodium montmorillonite film in 200 ppm malachite green
  • A closer look of the PVA-sodium montmorillonite film indicates that there is no defined glass transition as shown below:
PVA-sodium montmorillonite film in 200 ppm malachite green; no defined glass transtion curves

UV-Vis of MG-PVA samples

Table 1. Absorbance of Polyvinyl Alcohol Films in Malachite Green
  • Using quartz cuvettes, absorbance of 2 mL malachite green samples were collected.
  • 80 and 200 ppm malachite green samples were diluted to 100x and 50x, respectively.
  • The absorbance of each sample are listed on table 1.
Absorbance Spectra of PVA films in Malachite Green

Centrifuge of Ionic Liquid Exchange Clay

  • In the original protocol, the instruction called for vacuum filtration of our mixture, tributylhexadecylphosphonium bromide, through a 0.2μm nylon fiber.
  • A consensual decision was made that placing the mixtures in centrifuge would provide better results of separation.
  • The sample weighed the amount of 17.69 g. Addition of water was made to balance the viscous mixture, (1-hexadecyl)triphenylphosphonium bromide), from Eleni's group. The final weight was 27.42 g.
  • The mixture was centrifuged for 30 minutes at 4000 rpm, 4°C. The centrifuge used was the make of Thermo Scientific Sorvall RC 6+ Centrifufge.
  • The rotor chosen to perform the centrifuge was SH-3000 4700 max.
Thermo Scientific Sorvall RC 6+ Centrifufge
Centrifuge settings
SH-3000 4700 max rotor

  • At 10:53 AM, samples were observed to have three distinct layers; top and bottom layer were clay, and the middle was composed of water/supernatant.
  • The supernatant was collected and transferred into a 50 mL falcon tube. This was stored if additional analysis was needed in the future.
  • Two sets of washes are required for the exchanged clay. Each wash comprised of washing the clay with water to remove adsorbed NaCl and ethanol to remove remaining surfactants.
  • After the washes were completed by Dr. Hartings, the mixture was stored in an oven to evaporate excess water.

Powder X-RAY Diffraction of MG-PVA-clay samples

  • Eleni Kalivas executed the introduction of the usage of the powder X-RAY diffraction instrument. The make of the instrument is by Rigaku MiniFlex II.
  • The parameters set for the data collection made via the Standard Measurement interface are as follows:
    • 2° start angle
    • 40° stop angle
    • 0.5 inch sampling width
    • 1°/minute scanning speed
      • The original protocol stated a 1°/second scanning speed
  • Our group provided the blank PVA film which was placed in position 4. Other groups' PVA films were placed in the following order:
    • Position 1: Dr. Hartings' solid, sodium montmorillonite
    • Position 2: 8 ppm MG from Madeleine and Alicia
    • Position 3: group's 2 ppm MG
    • Position 5: 80 ppm MG from Melvin, Eleni, and Becca
    • Position 6: 200 ppm MG from Andrew, Michael, and Tami

Completion of Exfoliated Clay Film Synthesis