User:Sarah Burkhard/Notebook/CHEM 481 Polymers/2017/02/03

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Drying beads we prepared the last batch of beads (40 %) we made a plan to dry beads without neutralizing them : freeze dry beads: 1) punch holes in Falcon tube lid 2) decant water 3) put in -80 C freezer for 30 min 4) put in dry freezer in falcon tube for two days we went upstairs to use the freeze-dry Labconco FreeZone 1. You do not want to see any liquid in it. 1) Turn on, and wait until temperature drops to 0 C. 2) replace the little filter in the bottom 3) turn Vacuum on 4) push beaker into black shell want vacuum at decimals. Notes acid catalyzed hydrolysis of PvOH in oven would lead to further crosslinking. rotor used for centrifuge is SH-3000 BK (29) freeze drying is also called lyophilization. According to data from last semester, our largest beads were 600 um. The smallest were 50 um. We will start sieving with 45 mesh, 60 mesh , 80, and 120 mesh. This corresponds to 354 um, 250 um, 177 um, 125 um. The smallest sieve available is 63 um. If needed, we will use it later. To do find a sieve ask for cabbage