User:Sarah Burkhard/Notebook/CHEM 481 Polymers/2016/09/14

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Tasklist

  1. Update your notebook
  2. Place a link to your notebook in the section below
  3. Crosslink your film from Friday
  4. Make beads using the large batch profile
    • glutaraldehyde added last
    • use your clay solution to have a 10% clay in film composite
  5. Run XRD or DSC on your previously crosslinked films
    • one group will run XRD today and the other will run DSC
    • the groups will switch on Friday
    • if you have time, prepare beads using 10% activated carbon instead of the clay

Protocol

3 wt% bentonite solution instead of NaMT powder for the following protocol: Create a solution of 2.5 g PVA, 0.275 g NaMT, and 30 mL 10% HCl

3 wt% = 3 g bentonite / 97 ml water 0.275 g * 97 ml/3 g bentonite = 8.89 ml bentonite solution

we did not account for the change in volume . we kept the amount of HCl moles constant, which in effect diluted the concentration when using 10 ml of the solution for the beads formation. In following experiments we keep both volume and moles HCl constant; the only variable is water added.

Notes

For centrifuge: make sure they have equal weight. For malachite green: plot a graph and check for linear fit. Find r^2 .

films: with clay more brittle, but stronger half of film will be dried in oven. mass before oven of clay film: 1.24545 g. clear film mass (glut): 0.53 g . watchglass is labeled "A".

weight 1: 49.35200 g of beads 2: 53.903 equal weight: 48.666 48.65

centrifuge machine: RC 6 in Balance Room 3rd floor

  1. select rotor
  2. SH 3000 is rotor . max speed = 4700 rotations/minute
  3. set speed: 3000 rpm
  4. time: 1 min
  5. temperature: 25 degrees

take ethyl acetate out

34 ml starting point for beads titrate down until buret reads 44 ml add 1 ml glutaraldehyde ONCE, stir for 7 minutes at 320 rpm

add 7 ml sodium bicarbonate

replace glutaraldehyde to prevent sticking together ?

Friday: 20 percent clay mass of whole solution = 30 ml Hcl = 30 g

20 percent clay in PVOH. 2.5 g PVOH = 80 percent 2.5/.8 = total mass = 3.125 g multiply by 0.2 (20 %) to get mass of clay in g : 0.625 g . divide by 0.03 to get solution: 0.625 g / 0.03 g/ml = 20.83 ml bentonite solution

3 g / 100 ml solution = 0.03 g/ml

attention: the HCl will be diluted by the water added with the clay solution. Report the new concentration. Through adding 20.83 ml bentonite solution (97 ml H20/ 100 ml bentonite soluution) we effectively added 20.2 ml H20. This will dilute our 30 ml 10% HCL by 1/3 , so to 6.66 % HCl.

weight of clay film to be crosslinked: 1.43208 g

Xray

room 302, Rigaku

  1. power
  2. no warm-up required
  3. use deep 2 mm holder
  4. fill with silly putty least background
  5. need level surface
  6. piece of foil goes in flat : flatten it with spatula
  7. arrange inside machine so that length of sample is parallel to beam when disk has rotated
  8. turn on
  9. geiger meter to detect radiation leaks
  10. 'standard measurement '
  11. number of slots used change to yes
  12. create new file name
  13. select 35 stop angle
  14. change condition to 1 for all = sit still
  15. no spin with lose powders

We had 5 samples: pure clay, pure PvOH, pure silly putty, PvOH cross-linked film, and PvOH-10%clay-cross-linked film. We used a rotating sample holder.


For succesfully crosslinked films we expect broad diffraction, because that means no pattern in "slit width" or distance between atoms.

The angle given is the diffraction angle (actually twice diffraction angle). That's because it is refracted -- you get 2 beta (incident angle.)








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