@article{idolor_guha_berkowitz_geiger_davenport_grace_2021, title={Polymer-water interactions and damage detection in polymer matrix composites}, volume={211}, ISSN={["1879-1069"]}, url={https://doi.org/10.1016/j.compositesb.2021.108637}, DOI={10.1016/j.compositesb.2021.108637}, abstractNote={Polymer matrix composites have a tendency to absorb measurable moisture in nearly all operating environments. This absorbed moisture either becomes bound to the polymer network via secondary bonding interactions or exists as free water with negligible interactions. Damage creates new internal free volume where water molecules can exist in the latter state. This study introduces a novel basis for non-destructive examination in polymer matrix composites which leverages locally-higher concentration of free water in damaged areas. Experiments involved impact-induced sub-surface damage in a laminate prior to moisture exposure. Polymer-water interaction—determining the free or bound state of water—was characterized by near-infrared spectroscopy and microwave-range relative permittivity. Results show a direct correlation between the extent of local damage and higher relative levels of free water at damage sites.}, journal={COMPOSITES PART B-ENGINEERING}, publisher={Elsevier BV}, author={Idolor, Ogheneovo and Guha, Rishabh Debraj and Berkowitz, Katherine and Geiger, Carl and Davenport, Matthew and Grace, Landon}, year={2021}, month={Apr} }