User:James C. Schwabacher/Notebook/CHEM-571/2015/02/06

Biomaterials Design Lab

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February 6, 2015 MG absorption/rehydration trial PVA-Alg-Hectorite Procedure Procedure adapted from | Kuo-Ying Amanda Wu and Keith D. Wisecarver (1992)<br.> Modified from 1/28/2015 Prepare an aqueous solution of 13% PVA and 0.02% sodium alginate at 60°C (Stir plate on 3rd setting: ~68°C) 1 gram of PVA and 0.16 g of sodium alginate in 7 mL of water (12.5% PVA and ~0.02% alginate) Add alginate while stirring PVA-water solution ~0.1 g of nanocomposite should be added to this mixture where applicable Cool dissolved and mixed solution to 35°C Prepare 210 mL of saturated citric acid with 4% calcium chloride Add 8.4 grams (4%) of calcium chloride to 210 mL of water Add citric acid to saturation (32 g citric acid) 14.7g/100mL > 30.87 g/210 for solubility comparable to boric acid Add the PVA-Alg-Nanocomposite mixture drop-wise (by syringe) to the gently stirring (stir plate 3) citric acid-calcium chloride solution using a Pasteur pipette Stir for 2 hrs to allow solidification Rinse with water to remove excess reactants Measurements PVA-Alg-Hectorite PVA: 1.003 g Alg: 0.161 g Hectorite: 0.105 g Citric acid: 12.751 g CaCl2: 8.414 g PVA-Alg-NaMT vial: 706 mg PVA-Alg-NaMT upscale synthesis: 1470 mg Notes Rehydration attempt done on shaker, started at 12:28pm Beads on bottom of vial separate into individuals beads as they rehydrate Try lessening/removing citric acid Observation: beads that hold up seem to sink to the bottom where as the ones that fall apart float List of Characterization Techniques UV-vis absorption (equilibrium measurements) DSC: wet >before and after dehydration (structure & cross-linking) pXRD dry (structure & cross-linking) FTIR/solvent washing (bonds) Microscopy: dry and wet (swelling, bead size)?