Electron Spin Resonance (ESR)

Free Dangling Bond Electrons in Graphonyx Materials

Separate samples of Graphonyx material was Synthesized in various ways. The EPR showed that the samples had different levels of Dangling Bonds (defects) attachment.

Sharp peak observed (from spins in dangling bonds): peak to peak width ~ 4 Gauss Spin concentration: 7.8 mmol/cm3 g values is 2.0023 which is same with free electron-spin value (2.0023)

The existence of dangling bond elections has been demonstrated via using EPR characterization. While removal of dangling bond electrons from our Graphonyx material has proven to enhance its electrical and thermal conductivity, we have also discovered that the material with the dangling bonds (free electrons) appear to be excellent antioxidant/toxin scavengers. Tests are ongoing. * National High Magnetic Field Laboratory, Florida State University
Moderate broad peak observed: peak to peak width ~ 12 Gauss Spin concentration: 0.6 mmol/cm3The g values of 2.0025 is very close to free electron-spin g value (2.0023). * National High Magnetic Field Laboratory, Florida State University
Broad peak to peak width ~ 25 Gauss spin concentration: 0.5 mmol/cm3, The g values of 2.0044 is close to the free electron-spin g value (2.0023) * National High Magnetic Field Laboratory, Florida State University

Notes from National High Magnetic Field Laboratory Analysis, Florida State University ( Seven Samples Submitted)

We only observed signals from sample #1, #4 and #6. The major peaks of all three samples have g factors close to free electron g value - 2.0023, which indicates that the signals are from free electrons, such as dangling bonds, but not from transition metal impurities. The g values of #1, #4 and #6 are 2.0023, 2.0025, and 2.0044, respectively. The slight shift of g values between samples indicates that the free electron environment has changed for different samples, suggesting that local bond environments have changed.

Sample #1:  The spectra of sample 1 show a sharp peak. The peak to peak line width (Hpp) is ~ 4G. According to the reference you sent me, this peak could come from spins in dangling bonds. The spin concentration for this sample is ~7.8 mmol/cm3.

Sample #4:  The spectra of sample 4 show a moderate broad peak. The peak to peak line width (Hpp) is ~ 12G. This peak could be similar to either #1 or #6, a mixture, or other type of bonds.  The spin concentration for this sample is ~ 0.6 mmol/cm3
 
Sample #6:  The spectra of sample 6 show a broad peak. The peak to peak line width (Hpp) is ~ 25G. This peak could come from π electron spins. The spin concentration for this sample is ~ 0.5 mmol/cm3. Also, metal contamination is observed for this sample, most likely Mn. Mn is everywhere, such as in tap water.
 
Possible reasons for no signal from other 4 samples:
1). The number of free electron spins is too low to be detected by EPR.
2). No free electron spins.