Stevens’ associate professor, Pinar Akcora, has been named the lead of the National Science Foundation (NSF) supported study “Revealing Structure-Ionic Transport Relationship in Polymer-Ionic Liquid Ionogels.” Akcora and her team are focusing on how ions move within ionogels, with particular attention to the specific polymer chain conformations and ion distributions within the gels.
Ionogels are formed by trapping an ionic liquid inside a 3D polymer matrix, giving them the shape of a solid but the internal properties of a liquid. Similar to a hydrogel, like jelly or contact lenses, while ionogels have properties of both liquid and solid, they do not evaporate. Current hydrogels are susceptible to air and heat, leading to dehydration. On the other hand, the ionic liquid in an ionogel makes the entire structure stable even at high temperatures. Ionic liquids are made up of both positively and negatively charged ions, which allows for high conductivity. Akcora says, “Ionogels are fascinating because they let electricity flow while remaining soft, which makes them useful for sensors, soft electronics, drug delivery, and biomedical devices.”
Most research on ionogels is centered around strengthening the gels, whereas Akcora’s team will “explore what happens inside the gel at the molecular level.” The complex polymer chain interacts with the ions rather than simply “holding” the ionic liquid. The interaction between the polymer and ions can attract certain ions more than others, restrict ion movement, or change shape entirely — ion movement within the gel is not uniform. Essentially, since ionogels combine polymer networks with liquid salts, there exist areas where ions move differently than they would elsewhere and overall cause the gel to swell unevenly. One of the research team’s methods includes using a neutron scattering facility in Oak Ridge, TN. The technique will examine atom locations and molecule arrangements to further investigate how polymer conformations change and how ions are distributed in the gel.
Combined with the gel’s nonvolatility, the high thermal stability and conductivity make ionogels a prime material for future applications in wearable and flexible electronics, energy storage devices, and sensors. However, because of the higher concentration of ionic liquids, it is difficult to observe an ionogel with high conductivity and mechanical stability, an area where more research is needed. Akcora is most looking forward to ionogel applications in biomedical technology. Ionogels are incredibly flexible and conductive, lending themselves to wearable technology. Sensors created out of these gels can adhere to human skin and monitor physiological signals. Another biomedical application of ionogels is controlled drug delivery systems. If ionogels can contain drugs for controlled, localized, and consistent release, it would significantly streamline biomedical operations.
The study will take place over three years and is funded by the Chemical Structure and Dynamics (CSD) program within the NSF. The grant allows for increased exposure for Stevens’ undergraduate and graduate students’ research, and puts the next generation of researchers on a higher footing.
