Dielectric investigation of the sol-gel transition in the acrylamide/N,N′ methylenebisacrylamide system

The acrylamide/N,N′-methylenebisacrylamide gelation process was studied by time dependent measurement of real ε^I and imaginary ε^II parts of the complex dielectric permittivity. The measurements were carried out in the frequency interval 500 Hz to 13 MHz. Strong relaxation behavior of ε^I and ε^II was observed in all dielectric spectra during the transformation from the sol to the gel state. At all frequencies a maximum in the imaginary part of dielectric constant ε^II was observed. The gel point was found by extrapolating this maximum to zero frequency. The behavior of ε^I and ε^II related to the gelation mechanism is discussed.