User:Anh Do/Notebook/CHEM 481 Polymer/2016/09/07

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Making Beads using Bentonite 1. Protocol Using this protocol, scaled to produce 4.5 g of beads Beads contains 10% clay Volumn of bentonite 3wt% needed: 45*0.1*100/3 = 15 mL Mass of PVOH meassured: 4.5005 g Volumn of HCl 1.45M needed: 48*1.0/1.45 = 33 mL 2. Observations Beads were not formed. PVOH/Bentonite solution formed large clumbs in the container 3. Note Glutaraldehyde should be added after all PVOH/Bentonite solution is added to ethyl acetate. This way, the crosslinking process can happen more smoothly. PVOH film with Bentonite solution Mass of PVOH needed: 1 g Mass of PVOH meassured: 1.0006 g Volumn of bentonite 3wt% needed: 0.1/3*100 = 3.33 mL Volumn of water needed: 8.67 mL 12 mL - 3.33 mL bentonite solution = 8.67 mL water Follow the same procedure Crosslink films 1. Protocol Use a spoon to remove the films from the Teflon disk starting from the edges Use [this] protocol to crosslink the films 2. Observations (adapted from Sarah's notes) Mass of air dried films: PVOH+ Bentonite + Glutaraldehyde: 0.50790 g PVOH + Bentonite+ Glutaraldehyde + Glyoxal: 0.53745 g Heat acidic sulfate solution to 70°C Place films in heated solution for 60 min Used lowest spin setting to minimize entanglement since the stir bar interfere with the films Plastic buchner funnel can be used to separate bar from film, but 75 mL solution needed Rinsed films with deionized water (~ 5 sec) Glutaraldehyde film was soft, but had good integrity (clear, colorless) Glyoxal film had collapsed into sticky gel-like clump (translucent - white color) Placed films in 50 mL 1 M HCl at 70°C for 60 min (requires preheat; plan accordingly) Both films were transparent and rubbery Edges can break; care needed when handling with tweezers Rinsed films in water (~ 5 sec) and soak for 10 min Place films in 0.2 M NaHCO3 for 30 min Rinse films in water (~ 5 sec) and soak for 10 - 20 min Final rinse (~ 5 sec) and air dry for 2 days Noted film appearances prior to drying Glutaraldehyde film still had good integrity Glyoxal film was a clump and may have lost mass Both films had similar textures & colors: transparent & rubbery Next Lab Remake beads but add glutaraldehyde later Remake beads with bentonite powder