In the attached figure is shown the dependence of G' and G" on frequency (ω) for a aqueous suspension of sodium silicate and nanocrystalline cellulose (NCC).

I define the solid fraction as ϕ which is comprised by both silicate (95% wt.) and NCC (5% wt.). At the lowest concentration (ϕ = 50%) G" is lower than G' in all the frequency range and it corresponds to a viscoelastic solid behaviour. At ϕ = 60%, the slope of G'' increases more quickly than G' and the crossover point is observed at ωc = 1.5 rad/s, which indicates the occurring of microstructural changes in the system . By further increasing ϕ up to 70%, the crossover frequency (ωc) shifts to lower frequencies (the relaxation time moves to higher values i.e. delayed relaxation?) until no crossover point could be detected, thus being G'' > G' in the all investigated frequency range. The most similar behaviour I found in literature to the one I observed was for the so called "jammed" systems. Nevertheless, in the articles i found G' keeps constant or decreases after the crossover point, whereas in this case, both moduli keep increasing beyond ωc.

Does anyone could help me with the description/interpretation of this rheological behaviour? I thank you in advance.