User:Elizabeth Ghias/Notebook/Experimental Chemistry/2013/03/01

Experimental Chemistry

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Objective Prepare LB solutions for bacteria testing next week and crosslink the hydrogels that contain glutaraldehyde. Description Analyze FTIR By looking at the FTIR spectra of our films, we determined that the quaternary ammonium salt was present in our film. Therefore we will move on to bacteria testing. LB Broth Preparation Make one solution of 1.875 g LB broth in 75 mL water and make 8 solutions of 1.25 g LB broth in 50 mL water Cap all with foil Autoclave solutions for one hour Hydrogel Autoclaving Allow the PVOH film containing glutaraldehyde to dry completely. Prepare a solution of 100 mL H2O, 2 mL concentrated H2SO4, and 20 g Na2SO4 in a 150 mL beaker. (solution is referred to as glutaraldehyde fixant) Place stir bar in beaker and a Buchner funnel top (cap) over the stir bar Heat solution to 70°C (temperature on hotplate should be about 160) Place film in solution for one hour. Prepare 100 mL of a 1% HCl solution in a 150 mL beaker. Place a stir bar and an inverted buchner funnel into beaker. Heat HCl solution to 70°C Remove film from glutaraldehyde fixant and rinse with distilled water. Place film into HCl solution for 30 minutes. Prepare 0.2 M sodium bicarbonate solution. (1.68 g in 100 mL) After 30 minutes, remove the film from the HCl solution and place into the sodium bicarbonate solution (at room temperature) for about 15 minutes. Use tweezers to remove the film from the sodium bicarbonate solution. Rinse film with deionized water. The films were then allowed to dry over the weekend. Data No data was collected today. Notes When the hydrogels were crosslinked, they developed a fluid center, while having a squishy but somewhat dehydrated outside. After being left out to dry over weekend, the fluid center disappear and the films shrunk.