To Infinity and Beyond: The Amazing Hydrogels
This activity provides students with the background necessary to understand chelation—a type of bonding of ions and molecules to metal ions—to create hydrogels. During the activity, students use sodium alginate, an extract from brown seaweed, to create hydrogels. By using alginate-based compounds (in other words, compounds extracted from brown algae), these hydrogels are also nontoxic and non-inflammatory. All these properties make the alginates ideal for applications in pharmaceuticals, wound care, hygiene, and optometry.
Students test different hydrogel designs.Copyright 2022 Francisco J Padron, Rice University RET
Hydrogels are hydrated polymers that exhibit high elasticity and strength. sodium alginate is a natural hydrophilic biopolymer typically obtained from brown marine algae (such as seaweed), suitable for making hydrogels. The cross-linked polymer swells up in contact with water to form an insoluble hydrogel, with properties intermediate between those of a solid and a liquid. This unique material can be utilized in medicine for drug delivery and implantable medical devices. Potential uses are in tissue repair, cartilages, herniated discs, and implants as bio printed (3D printable) material.
By the end of this activity the students should be able to:
- Create a hydrogel using the crosslinking process.
- Understand and explain the chelation of a polymer using the ionic crosslinking process by exchanging a monovalent metal (Na+1) with a divalent metal (Ca+2).
- Explain what a hydrogel is and its different applications.