Week Nine Update
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.
Week Eight Update
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.
Week Seven Update
Week Six Update
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.
Week Five Update
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.
Week Four Update
Week Three Update
We discussed the option of mixing other substances in with our hydrogel, and ultimately decided on borax (sodium tetraborate). We will cross-link the borax with PVA, which will strengthen the mechanical properties.
In the lab this week, we will set up our control and experimental hydrogels as follows:
Week two was our first time in the wetlab. We took this opportunity to build our first hydrogel using PVA and DI water.
Week One Update
We came up with a preliminary idea for our project, which involved an edible hydrogel that filtered out salt water as it formed. This idea was ultimately thrown away, because the chemistry would have been way too advanced for our level. We went back to brainstorming for a new topic of research.
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.
Week Eight Update
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
Week Seven Update
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 formed was very sticky and the researchers considered compression testing it immediately, but didn’t want to deposit the substance onto the compression testing machine, so they decided to wait for freeze/thaw cycles to be done on the samples.
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.
Week Five Update
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 eliminate the heat testing and focus more on making as many samples as time permits for the repeated impact and compression testing.
Berk assisted in performing various activities in the lab related to hydrogel synthesis. Some tasks performed include measuring out enough PVA to create 10% solution, cutting foil to line petri dishes, measuring out enough Borax to make 4% solution, and cleaning after his lab members. He also took photo and video documentation of the conditions of the samples and of the operations performed by the researchers.
Carl made hydrogel test samples with Berk and Rosie. We decided to increase the percentage of PVA from 5% to 10% for all future samples. We decided to do this because all of our samples of pure PVA were liquid after the freeze/thaw cycles. We made 13 PVA samples and 8 PVA/Borax samples. We also lined the petri dishes with tinfoil.
Week Four Update
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 and thaw method that would be used to strengthen the hydrogel samples, where it was discovered that the method that will be done for the samples in the lab will in fact be effective in creating a stronger hydrogel by forming PVA crystals. Other articles related to this concept by highlighting how certain polymeric chains within the hydrogel also contribute to the overall mechanical properties of the hydrogel, as well as fiberglass doing so and being a beneficial component of sporting equipment.
Sara researched the effects of fiberglass in hydrogels to help further knowledge of how the hydrogels will react to it. An article was found that discussed the strength and mechanical abilities of silica hydrogels that contain fiberglass. It was discovered that the fiberglass does help to reinforce the hydrogel, and more research is being done to see how it will effect PVA hydrogels.
Berk assisted in the lab by completing assorted tasks related to the synthesis of plain PVA and PVA+borax hydrogels. These activities include but are not limited to gathering the required amount of water, pouring PVA samples into the water, labeling petri dish covers, pouring mixed samples of PVA into petri dishes, and cutting paper towels to separate petri dishes in a stack from each other. Berk additionally took photos and videos to document the different phenomena that were observed during the time spent in the lab. Berk Berk Berk Berk Berk Berk Berk
Week Three Update
We discussed the option of mixing other substances in with our hydrogel, and ultimately decided on borax (sodium tetraborate). We will cross-link the borax with PVA, which will strengthen the mechanical properties.
In the lab this week, we will set up our control and experimental hydrogels as follows:
The preparation of the PVA hydrogel will be as follows:
- Prepare 100 mL of PVA solution by adding 4 (or 8) grams of PVA to 100 mL of water and heating to 80℃
- Mix solutions together until gelled
- Press gel into petri dish molds
- Freeze gel for 12 hours at -20℃, thaw at 20℃, repeat 3x
The preparation of the PVA and Borax hydrogel will be as follows:
- Prepare 100 mL of PVA solution by adding 4 (or 8) grams of PVA to 100 mL of water and heating to 80℃
- Prepare 30 mL of Borax solution by adding 2.4 grams of Borax to 30 mL of water
- Mix solutions together until gelled
- Press gel into petri dish molds
- Freeze gel for 12 hours at -20℃, thaw at 20℃, repeat 3x
The PVA hydrogel will act as our control, while the adding of borax will be the experimental.
Week Two Update
Week two was our first time in the wetlab. We took this opportunity to build our first hydrogel using PVA and DI water.
As can be seen from the photo, the concentration of hydrogel to liquid was not ideal. We took this into account when planning the next hydrogel formulation: opting for much less liquid.
This week's discussion also involved different additives available to make our hydrogel stronger. The two most likely substances turned out to be fiberglass and borax, because they will increase the shock absorption of the PVA hydrogel. This will be explored further in week three lab.
We came up with a preliminary idea for our project, which involved an edible hydrogel that filtered out salt water as it formed. This idea was ultimately thrown away, because the chemistry would have been way too advanced for our level. We went back to brainstorming for a new topic of research.
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