A New Way to Power Chemical Reactions
New research from MIT discovered a new way where exothermic solvent absorption could be effectively converted into a usable electric potential using carbon nanostructures.
The research is completed by the Strano Research Group from the department of chemical engineering at MIT with Professor Michael S. Strano as the senior author. The lead authors of the study are MIT graduate student Albert Tianxiang Liu and former MIT researcher Yuichiro Kunai. Other authors include Volodymyr Koloman, Hyunah Kim, and Amir Kaplan post-doctoral researchers at MIT, and recent/formal; graduate students, GE Zhang, Anton L. Cottrill, and recent MIT alumni Rafid Mollah and Yannick Eatmon.
Schematic illustration of Janus microparticles generating electricity to power electrochemical redox reactions (e.g., Fe2+ → Fe3+ or Cu2+ → Cu0) in situ, in lieu of a potentiostat as a voltage source. Image courtesy of MIT Researchers
Several studies in this realm have been conducted since 2003.. Carbon nanotubes were demonstrated as thermo-power generators in 2010 by Strano. When coated with a layer of fuel a carbon nanotube moving pulses of heat, or thermopower waves, travel along the tube, creating an electrical current. The research literature was based on previous studies.
SWNT is also expressed as single-walled carbon nanotubes formed by removing water impurities via a water/hexane system. What remains are catalyst residues, which are purified using hydrochloric acid. Then the samples are ground and dried to form purified SWNT powder. To form the SWNT networks 30 mg of SWNT powder was merged with 50 μL of DI-water and put on a Teflon sheet. Then the mixture was hot-pressed at 50 °C for 10 minutes on a 5-ton press scale. Then the SWNT network was dried overnight and then diced into 500 µm thick sheets.
To create the carbon Janus particles the SWNT network was diced into 250 µm cuboids. One side of the sheets was covered with a barrier polymer and the other side was left exposed so it could have access to the surrounding solvent.
Then the particles are submerged in an organic solvent so the unprotected surface has the ability to pull electrons out of them.
Surface profile of two 500 µm × 250 µm × 250 µm o-SWNT/PTFE Janus particles (color bar range, 0–500 µm; scale bar, 100 µm). Image courtesy of MIT Researchers
For electrical measurement, the SWNT network was made with copper electrodes. By connecting the voltage and current meters, testing the electrical output becomes possible. To evaluate the basic electrical properties of the SWNT network, electrical contacts were made on both sides of the network using copper electrodes. Then, the particles were immersed, with the electrodes connected to the voltage meter or current meter, into solvents while measuring the voltage or current output.
The research was funded by the U.S. Department of Energy and a seed grant from the MIT Energy Initiative.