ABSTRACT
The use of electron paramagnetic resonance (EPR) imaging for "dynamic samples" to investigate transport phenomena has been accomplished in just a few laboratories. Existing data on rotational molecular dynamics in the systems suggest that one should expect very strong coupling between the rotational and translational motions of rod-like macromolecules. The EPR imaging of dynamic samples has been studied in other laboratories. The spin probes can be used as markers for the imaging of diffusion only if the EPR signal is independent of the concentration. In standard EPR-spectroscopy, the spectrum is recorded by maintaining a constant microwave frequency and varying the magnetic field over some range, Bs, around the central-field value, Bo. Since the cavity sensitivity S varies with position, the effective concentration-profile "seen" by the dynamic imaging of diffusion (DID)-EPR technique is the product S. The most important part of the DID-EPR experiment is a system generating a linear magnetic-field gradient across the cavity.
