User:Alicia Rasines Mazo/Notebook/CHEM-581 Experimental Chemistry I/2014/09/24

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Tasks for September 24

  • To continue processing films from last week
  • To make new films with exfoliated clay
  • To run AA on the arsenic samples
  • To measure fluorescence of Rhodamine dye

Preparation of 10% wt new exfoliated clay films

  • 1.0042 g 22,000 PVA, 0.1101 g of of exfoliated tributylhexadecylphosphonium bromide (THP Br) and 7 mL of distilled water were used to make up a 10% wt PVA-exfoliated THP Br film. Note this clay was prepared by Jame's group.
  • 1.0028 g 22,000 PVA, 0.1107 g of exfoliated tributylhexadecylphosphonium bromide (THP Br) and 7 mL of distilled water were used to make up a 10% wt PVA-exfoliated THP Br film.
  • Heated at approx. 80ºC with gentle stirring until all crystals were dissolved
  • Allowed to cool down to room temeprature
  • Added 0.8 wt% 0.5 mL glutaraldehyde under hood
  • Stirred for 3 min to ensure homogeneity
  • Poured into teflon dish and allowed to dry

Completing synthesis of films

  • Soaked in sodium sulfate for 1h, put into 0.1% HCl for 30 min, then sodium bicarbonate solution for a further 15 min.

Run AA on As samples

  • James and Eleni made made As standards: 0, 10, 20, 30, 40 and 50 ppm.
  • Diluted the 100 and 150 ppm As sample solutions so that:
    • 150ppm(v1)=30ppm(10mL)
    • v1=2 mL of 150 ppm As solution. To be diluted to 10 mL with distilled water.
    • 100ppm(v1)=25ppm(10mL)
    • v1=2.5 mL of 100 ppm solution. To be diluted to 10 mL with distilled water.
  • Note: 50 ppm As solutions were left undiluted, as they were within the range of the range calibration curve

To be done at a later date since As lamp was burnt out

Measuring fluorescence of Rhodamine dye by films

Note: the initial concentration of rhodamine was incorrectly labeled as 159μM, actual concentration was 1.9 mM
Solutions were made for 20, 10 and 1 μM R6G by:

  • Adding 12.578 mL of 159μM rhodamine dye solution to a 100 mL volumetric flask and making up to the mark with distilled water to make up 20μM R6G.
  • Adding 6.289 mL of 159μM rhodamine dye solution to a 100 mL volumetric flask and making up to the mark with distilled water to make up 10 μM R6G.
  • Adding 0.629 mL of 159μM rhodamine dye solution to a 100 mL volumetric flask and making up to the mark with distilled water to make up 1μM R6G.
  • Corrections:
  • Adding 12.578 mL of 1.9 mM rhodamine dye solution to a 100 mL volumetric flask and making up to the mark with distilled water to make up 239.4 μM

10mL of each R6G dye solution were added to the PVA and PVA-Clay glass vials and the glass vials were placed inside a dark drawer to allow the films to soak the fluorescent dye.

  • Adding 6.289 mL of 1.9 mM rhodamine dye solution to a 100 mL volumetric flask and making up to the mark with distilled water to make up 119.7 μM

10mL of each R6G dye solution were added to the PVA and PVA-Clay glass vials and the glass vials were placed inside a dark drawer to allow the films to soak the fluorescent dye.

  • Adding 0.629 mL of 1.9 mM rhodamine dye solution to a 100 mL volumetric flask and making up to the mark with distilled water to make up 11.97 μM

10mL of each R6G dye solution were added to the PVA and PVA-Clay glass vials and the glass vials were placed inside a dark drawer to allow the films to soak the fluorescent dye.

Film Solution Vial mass (g) Vial + film mass (g) Film mass (g)
PVA film 239.4 μM R6G 13.0803 13.1813 0.1010
119.7 μM R6G 13.0713 13.1497 0.0784
11.97 μM R6G13.0403 13.1337 0.0934
PVA-Clay film 239.4 μM R6G 13.0828 13.2554 0.1726
119.7 μM R6G 12.9552 13.0732 0.1180
11.97 μM R6G 13.0198 13.1377 0.1179

Measuring absorbance of R6G dye by polymer and clay films

  • UV-Vis Results
    • PVA film
PVA in R6G dye left in solution (μM) R6G dye absorbed by film (μM)
239.4 μM R6G 254.3* (Retake measurement)
119.7 μM R6G 53.8 65.9
11.97 μM R6G 1.076 10.894

10 mL of R6G solution were added to each vial, so that if 10.894 μM were absorbed from the 11.97 μM solution, moles absorbed=(10.894×10-6moles)/0.010L=0.0010894 moles.

  • mass of R6G dye absorbed=0.0010894 moles × 479.02g/mol=0.5218g
  • 11.97 μM: (0.5218 g R6G/0.0934 film)= 5.59 g R6G/g film
  • 119.7 μM: 40.3 g R6G/g film
  • 239.4 μM:
    • PVA-Clay film
PVA-Clay in R6G dye left in solution (μM) R6G dye absorbed by film (μM)
239.4 μM R6G 38.79 200.6
119.7 μM R6G 15.09 104.6
11.97 μM R6G 0.776 11.19

10 mL of R6G solution were added to each vial, so that if 11.194 μM were absorbed from the 11.97 μM solution, moles absorbed=(11.194×10-6moles)/0.010L=0.0011194 moles.

  • mass of R6G dye absorbed=0.0011194 moles × 479.02g/mol=0.5362 g
  • 11.97 μM: (0.5362 g R6G/0.1179 film)= 4.55 g R6G/g film
  • 119.7 μM: 42.5 g R6G/g film
  • 239.4 μM: 55.7 g R6G/g film
  • Fluorescence data
    • PVA film
PVA in R6G dye left in solution (μM) R6G dye absorbed by film (μM)
239.4 μM R6G 227.9 11.5
119.7 μM R6G 39.28 80.42
11.97 μM R6G 1.525 10.445


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