Processing, and Characterization of Alginate Tubes — 91p — Logan Merriam, Logan Merriam, Laura Brunmaier, Arushi Thatola, Izzy Grinager, Abigail Flanegan, Kara Huse, Travis Walker

Alginate is a naturally occurring polysaccharide derived from brown algae, which can be extracted into a sodium alginate (NaAlg) form that crosslinks with bivalent cations, and has several biomedical applications such as wound dressings, drug delivery, and tissue engineering. Shear rheology was used to characterize the viscosity and critical overlap concentration (C*) to assess processability. A co-flow setup was utilized to fabricate NaAlg tubes by pumping 2 wt% NaAlg around an 8-gauge core of aqueous CaCl₂into a CaCl₂ bath for complete crosslinking. The data was used to construct a phase-shift diagram documenting several hundred extrusion points, outlining the boundaries for successful extrusion of NaAlg tubes. The tubes were characterized by burst pressure and tensile strength tests to measure the mechanical properties of the material. This work aims to establish relationships between concentration relative to C*, rheological properties of different alginate solutions, extrusion limits of NaAlg tubes, and their subsequent mechanical properties, thereby defining process-structure-property-performance relationships for NaAlg.

South Dakota School of Mines & Technology
Laura Brunmaier