Objectives
- Standardize 1 M NaHCO3 solution.
- Soak PVOH (MW 22000) in HPLC grade H2O to determine change in mass due to swelling.
- Soak PVOH (MW 22000), 1 mL glutaraldehyde, 1 mL porphyrin in 2 wt% H2SO4 until the film turns green. Then soak the film in salt solution and take UV-vis of the film.
PVOH (MW 22000) Film Swelling
- Change in mass of PVOH (MW 22000) films after soaking in 10 mL HPLC grade H2O for three days.
| Crosslinked Film
| Date Prepared
| Initial Mass [g]
| Final Mass [g]
| ΔMass [g]
| % Change []
|
| PVOH(22K),0.5mLGA,NaMT | 11/2/2012 | 0.0241 | 0.0871 | 0.063 | 261.4107884
|
| PVOH(22K),0.5mLGA,1mLPP | 10/26/2012 | 0.0398 | 0.1132 | 0.0734 | 184.4221106
|
| PVOH(22k),0.5mLGA,0.99mLPP | 10/19/2012 | 0.0312 | 0.0872 | 0.056 | 179.4871795
|
| PVOH(22k),8.24µLGA,50%CECMT,CuSO4exch. | 10/17/2012 | 0.0113 | 0.0242 | 0.0129 | 114.159292
|
| PVOH(22k),8.24µLGA,100%CECMT,CuSO4exch. | 10/17/2012 | 0.0048 | 0.0095 | 0.0047 | 97.91666667
|
| PVOH(22k),1mLGA,50%CECMT | 10/4/2012 | 0.0138 | 0.0294 | 0.0156 | 113.0434783
|
| PVOH(22k),1mLGA,100%CECMT | 10/4/2012 | 0.0144 | 0.0307 | 0.0163 | 113.1944444
|
| PVOH(22k),1mLGA,1mLPP,less colored | 10/24/2012 | 0.014 | 0.0241 | 0.0101 | 72.14285714
|
| PVOH(22k),1mLGA,0.1gNaMT,CuSO4exch. | 10/17/2012 | 0.0102 | 0.0222 | 0.012 | 117.6470588
|
| PVOH(22k),0.5mLGA,1mLPP | 10/24/2012 | 0.0279 | 0.0596 | 0.0317 | 113.6200717
|
| PVOH(22k),1mLGA,1mLPP | --- | 0.0369 | 0.0687 | 0.0318 | 86.17886179
|
| PVOH(22k),8.24µLGA,100%CECMT | --- | 0.0447 | 0.1038 | 0.0591 | 132.2147651
|
| PVOH(22k),0.5mLGA,100%CECMT | 10/19/2012 | 0.0115 | 0.0425 | 0.031 | 269.5652174
|
- The films that displayed the smallest percent change in mass were PVOH(22K)+0.8wt%GA+100%CECMT (exchanged with CuSO4) and PVOH(22K)+1mLGA+1mLPP.
- The films that displayed the largest percent change in mass were PVOH(22K)+0.5mLGA+100%CECMT, PVOH(22K)+0.5mLGA+NaMT, and PVOH(22K)+0.5mLGA+1mLPP.
- Effect of ion exchange?
- It appears that adding 0.5 mL of glutaraldehyde to the films does not induce sufficient crosslinking to prevent swelling. However, 1 mL of glutaraldehyde seemed to reduce the degree to which the films swelled.
- Overall, most films displayed about a 100% increase in mass. In other words, their mass approximately doubled due to swelling.
Standardization of NaHCO3
- Protocol
- Weigh out 20 g of potassium hydrogen phthalate (KHP).
- The mass was divided into thirds, and then dried in the oven at 90°C for 48 hours.
- Each sample was divided in half again to give six samples of KHP total.
- One sample was placed in a 100 mL beaker and 2 drops of bromothymol blue was added.
- 1 M NaHCO3 was poured into a titration buret and the initial volume was recorded.
- The KHP was titrated with the NaHCO3 solution until the solution in the beaker turned blue and stopped fizzing.
- The process was repeated for two more KHP samples.
- The number of moles in the NaHCO3 solution was calculated.
CALCULATIONS
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