Diffusion to fractal surfaces. II: Verification of theory

摘要: Decay of the diffusion controlled current particles diffusing from an initially homogeneous medium to a completely absorbing fractal boundary was previously shown exhibit t−α time-dependence instead conventional t−12 one with exponent α being determined by dimension, Df, interface as =(Df−1)/2. In electrochemical terms this corresponds generalized Cottrell equation (or Warburg impedance) and can be used describe frequency dispersion caused surface roughness effects. We verify predicted behaviour for surfaces Df>2 (rough interface), Df<2 (partially blocked or active islands on inactive support). addition, decay kinetics is valid both contiguous non-contiguous surfaces. Computer simulation, mathematical model, direct experiments well defined electrodes are tools verifying law different The power observed, α(Df) relationship seen prevail in each case.