User:Moira M. Esson/Notebook/CHEM-581/2013/04/17

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Objectives Run X-ray diffraction on all prepared 130MW PVA/clay films. Run Diffusion Testing on all microsphere samples with Rhodamine 6G added. Prepare for pressure testing of microspheres. Finish running DSC of all hydrogel(PVA 130) samples and a Rhodamine 6G sample. X-ray The general protocol for X-ray diffraction described on 2013/04/12 was followed. Due to the analysis of films, invisible scotch tape was used to tape the films onto the pan. The scotch tape was placed on the edge of the films. A plain scotch tape X-ray sample will be taken and will be subtracted from all film samples. All x-ray spectra will be uploaded once collected. Only 50:50 PVA:clay samples were run on the x-ray. The prepared 50:50 PVA130:110% LP film sample formed a powder after being allowed to completely dry. Figure 1. Disintegrated 50:50 PVA130:110% LP after cyclic freeze-thaw method Microspheres Diffusion Testing: The general protocol for diffusion testing described on 2013/04/03 was followed. Prior to diffusion testing, the samples were sonicated. All diffusion spectra will be uploaded when analyzed. It appears that diffusion of dye occurs much more rapidly for the prepared microspheres(true microspheres in comparison to the samples run with PVA146). This may be due to the smaller surface area of the microspheres in comparison to the hydrogels. This may serve as an advantage, as less sheer pressure may be needed to facilitate the release of dye. Pressure Testing: Due to the small size of the prepared microspheres, it was determined that an unmodified pipette would not be used for pressure testing. The small size allowed the microspheres to go straight through an unmodified pipette. Due to the small size, a new version of a modified pipette will be used during the next lab session. 5 of these modified pipettes were prepared. Figure 2. Microsphere Modified Pipette to be used for Pressure Testing DSC The general protocol for DSC analysis was followed. Specific DSC parameters ato analyze the following PVA/clay samples included the following: # Equilibrate sample at ~ -40°C # Ramp sample temperature up from 20-240°C # Ramp sample temperature down from 20-(-40°C) # Repeat segment #2 again The samples were re-run due to (a.) lack of gas towards the end of the list of samples analysis and (b.) spectra were not able to be opened because only two data points were obtained for each sample. It is believed that only two data points were collected because the samples were run before reaching the flange temperature. Prior to run, the flange temperature was allowed to be reached.