Publication Date

Fall 2017

Degree Type


Degree Name

Master of Science (MS)


Biomedical, Chemical & Materials Engineering


Melanie McNeil


alginate, design of experiments, diffusion, diffusivity, factorial analysis, polymerization

Subject Areas

Chemical engineering


The purpose of this work is to develop an experimental setup with associated mathematical analysis to analyze the changes in diffusivity through calcium alginate gel beads made under different polymerization conditions. The diffusivity of the solutes glucose and tryptophan was calculated by measuring the concentration change over time as solute diffused out of the alginate spheres and into the bulk. The alginate beads were generated using different polymerization conditions following a two-level, three-factor, full-factorial matrix with alginate concentration, cross-linker concentration, and cross-linking time as the factors. The diffusivities showed variations between different conditions, which were analyzed to determine the main effects. No factors or interactions were found to affect the diffusivity of tryptophan. The main effects on glucose diffusivity were the cross-link time and the interaction of alginate concentration and cross-linker concentration. The initial concentration absorbed by the gel matrix showed variation across different polymerization conditions. Statistical analysis was repeated for the initial concentration. Cross-linking time and the interaction between cross-link concentration and time were the main effects on glucose initial concentration, and no factors influenced tryptophan initial concentration.