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Hydrogels  are  polymeric  matrixes that swell but don’t dissolve in water . They swell because of their high thermodynamical affinity.  Hydrogels absorb large amounts of water, trapping it inside their large network of covalent bonds. This creates a large network of saturated hydrogel molecules that has special mechanical properties like shock absorbance and a high specific heat capacity.  These characteristics, coupled with a high versatility and a high tunability of material’s properties, lead to deep research and exploitation of hydrogels.  There are many applications for hydrogels, including contact lenses and diapers, but research is still being done about them to this day. Of the available hydrogels provided for us: Polyvinyl Alcohol (PVA)                                 Gelatin Agarose We will be using PVA as our base hydrogel and experiment with other...

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 Th...

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.

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.

What are hydrogels? Hydrogels are polymeric substances that, due to their structure, can absorb large amounts of water. What are some properties of hydrogels? Specific hydrogels can exhibit volume changes when responding to external stimuli, such as pH levels, solvent quality, temperature, electric currents, and more. How do they work? Hydrogels absorb large amounts of water, trapping it inside their large network of covalent bonds. This creates a large network of saturated hydrogel molecules that has special mechanical properties like shock absorbance and a high specific heat capacity. What can hydrogels do? There are multiple applications for hydrogels. Some examples are drug delivery, agriculture, and wound dressing. Can hydrogels absorb things beside water? “Hydro” means water. Hydrogels need to absorb water to be hydrogels. However, they can also absorb water based solutions. Can I eat my hydrogel? Some hydrogels are edible, like gelatin, ...

Given that many of us were athletes at one time, we decided to use our hydrogel study to formulate a more effective replacement for foam in sports safety equipment. We came up with this idea after questioning the shock absorption properties of hydrogels. This, combined with dual studies in the degradation of hydrogels in high heat and ability of hydrogels to maintain composure will help us determine whether a hydrogel could be a suitable replacement in the safety precautions of athletes. There are three hydrogels provided to us and three available liquids to test with, these are as follows: Hydrogels Polyvinyl Alcohol (PVA)                                 Gelatin Agarose Liquids Tris/Borate/EDTA buffer (TBE) Phosphate buffered saline (PBS) Deionized Water (DI Water) We will be using PVA as our base hydrogel and experiment with other additives such as fiberglass and borax to streng...

Karli Akin Major: Materials Science and Engineering Hometown: Morrisville, Pennsylvania Email: kna48@drexel.edu Karli is a freshman at Drexel and an an active member of the Society of Women Engineers and Engineers Without Borders here at Drexel. She is fond of traveling and hopes to study abroad or take part in an intensive course abroad in the near future. Sara Brodrecht Major: Materials Science and Engineering Hometown: Doylestown, Pennsylvania Email: svb33@drexel.edu Sara is a freshman at Drexel University. She is a member of the Society of Women in Engineering here at Drexel. Sara hopes to study abroad for a semester. Carl Furner Major: Materials Science and Engineering Hometown: Harwich, Massachusetts Email: ctf46@drexel.edu Carl is a freshman at Drexel and is an active member in the Drexel Steel Bridge club. He also plays for the club lacrosse team. Carl is interested in an international CO-OP and studying abroad in France. ...