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Sara, Rosalie, and Karli did compression testing on the remaining samples and conducted all necessary calculations that we will use to compare the samples from week to week. In addition to this, Berk worked on the final project report and presentation. Carl made the final product, a hydrogel pad in a plastic mold using 4x the normal amounts of hydrogel per batch.

Berk and Karli: Worked in lab on making 20% w/v hydrogel test samples with both borax and fiberglass. Solved problems with air bubbles in the test samples and the low degree of water retention in the hydrogel. Sara and Rosie: Worked on compression testing of last week’s samples. Worked through issues with the air bubbles left in the samples, as well as the sinking that happened over the weekend. Developed the excel charts for calculating the young’s modulus of each sample under compression Carl: made edits and comments on the final draft to reflect the discussion with Dr. K, as well as helped berk and Karli troubleshoot the synthesis of hydrogels. Also discussed with the group ways that we can improve the final report

Rosie, Sara, and Karli contributed by observing the samples from last week and discussing the calculations done from last week’s compression testing through Young’s modulus. We had initially anticipated to perform compression tests on the samples made from last week’s lab, yet we had determined that their liquid-like composition rendered them usable.Through observing these samples, we hypothesized that we ultimately needed to change the amounts of the chemical composition of materials of the new hydrogels and that we will be using our new hydrogels in the compression testing next week. Carl and Berk worked in the lab to create a new hydrogel with 150 mL of deionized water, 30.285 g PVA, and 0.185 g of Borax. Carl worked with the mixing of the materials and casting of the mixed product and Berk measured out the materials and prepared the petri dishes for use. The water and Borax were mixed together, and once fully dissolved, the solution was added to the PVA and mixed. The hydrogel ...

This week we were finally able to compression test our samples. However, the only samples that were eligible were from the first opportunity in the lab. Everything else we have created has been way too runny. We are working to develop a better formula and process to minimize these issues. The compression testing went smoothly, however, and calculations were done to be able to test these to the next batch of samples we make. The new samples will have the borax mixed with the water first, instead of the PVA. We also added some PVP in the hopes of strengthening the shock absorption properties. We will also be exposing samples to the air as they set, so they will become more firm.

Rosalie worked tirelessly in the lab to assist in making more samples and analyzing the samples that have already been made. She finally was able to implement the idea of lining petri dishes with tin foil. The concentration of PVA was increased, so more analyzation between the different percentages will be required later. Sara researched more about how to strengthen PVA and what additives might help to do that. One article was found where they used acrylic acid to strengthen PVA and then tested it to see its strength. The characteristic found to be strengthened the most by this process was temperature. More research will continue to be done. Karli researched heat testing on the hydrogels and determining if there would be enough time and materials to do so by the end of the lab period. Interestingly, one article stated that heating the material will decrease the crosslinking degree of a hydrogel. Taking this into consideration, and as far as time management goes, it may be wise to...

Rosalie helped in the lab by observing and handling last weeks samples. She facilitated the thawing and tested their general shape and composure. She also brainstormed better ways to make and store this week’s samples, as well as assisting with their formulation. Rosalie has updated the blog and set the schedule for the freezing and thawing cycle of the hydrogel samples. She will come to the lab tomorrow to take the first turn in switching them. Carl produced 18 new hydrogels with Berk. 12 PVA 4% w/v and 6 PVA 4%/Borax 4% samples. Carl discussed the merits of lining petri dishes with Rosalie, but did not end up doing it. Carl discovered that PVA and Borax hydrogels from last week were not mechanically sound, but Carl hopes that the freezing/thawing process will aid in the mechanical stability of the samples. Karli contributed by finding articles on topics pertaining to the concepts and techniques that will be used in the project. One article that was found related to the freeze ...