Electrical Response of Chemiluminescent Materials
Authors:Louis Magallon, Stephen Tsui
Mentor:Stephen Tsui, Physics Department Assistant Professor , California State University San Marcos
Author: Louis Magallon, California State University San Marcos
Mentor: Stephen Tsui, PhD, Physics Program, California State
University San Marcos
Every material possesses a characteristic electrical response, be it conducting or insulating. Even physical processes can be investigated by examining their current-voltage characteristics or probing their frequency dependent electrical behavior. A technique common in physics and electrochemistry is impedance spectroscopy, which is a frequency dependent sweep of the in-phase and out-of-phase voltage response to an input sinusoidal voltage. We utilize this technique to compare the electrical behavior of active chemiluminescent solutions. A home-made parallel plate capacitor cell was inserted into solution, and the dielectric response was measured via lock-in amplifier swept from 0.3 Hz to 100 kHz. We compared the behaviors of water, commercial glowstick material, homemade chemiluminescent solution, and a weak bioluminescent sample. The light-emitting samples were more conducting than the water sample as a result of their active charge transport processes, but the solutions themselves were not good conductors. The off-phase responses demonstrated behaviors appropriate for fit to resistor-capacitor network models. Future efforts of this project will be to look for unusual frequency responses outside of the range of our current lock-in amplifier and attempt to correlate the impedance data with photometry measurements of the active materials.