User:Dominique Brager/Notebook/481 Notebook/2017/02/08

Biomaterials Design Lab

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Objective Took beads out of freeze dryer Boiled cabbage leaves Swelled Beads Description Freeze dried beads were black and clumped into solid rocks. Potentially the lower pressure was enough to let the hydrolysis reaction happen. Weighed Beads Swelled Beads Places beads in containers with enough water to coat them Data Mass of Beads 10% Beads: 0.811 g 25% Beads: 1.007g 40% Beads: 1.123g Beads Observations Were in solid clumps Poking them with a stick and shaking them did not separate them into beads Beads were a blackish-greenish color Upon placing the beads into water they separated a little into beads and turned a lighter green color After about half an hour of sitting in water, water solution had a pH of about 1 according to pH test. 40% beads were fasted to turn green. Turned a richer, greener green 25% Beads took longest to turn green Color somewhat between 40% and 10% 10% Beads Turned a yellower green color (more like seaweed) Cabbage Dye Boiled dye until most of pigmentation came out Checked effect of pH on color Dye is neutral Checked effect of pH on dye color Beaker on the left is acidic. Beaker in the middle is neutral. Beaker on the right is basic. Ran UV-Vis on Dye and Serial Dilutions as follows: Stock solution, 4:1 Stock to water, 3:2 Stock to water, 2:3 Stock to water, and 1:4 Stock to water. Neutral Dye absorbed between 545-548 nm Got the following UV-Vis Spectrum: Made trendline for absorbance of serial dilutions. Percentages are based of stock solution. 100% = same concentration as stock solution. 20% is 1:4 stock to dye. Etc. Notes https://www.google.com/patents/US6046272 Link to patent that explains discoloration in PVA