Cellulose nanofiber-multi-walled carbon nanotube nanocomposites: Resonant electrical transport induced by LC network formation

This work investigates the alternating current (AC) conductivity behavior of cellulose nanofiber (CNF)-functionalized multi-walled carbon nanotube (MWCNT) nanocomposites, with particular emphasis on percolation and resonance phenomena. It is observed that the AC conductivity exhibits a pronounced nonlinear dependence on frequency at intermediate MWCNT contents. At 10 wt. % MWCNT content, charge transport is dominated by fluctuation-induced tunneling mechanisms, leading to a strongly frequency-dependent conductivity response. Increasing the nanotube content to 15 wt. % results in a stable, saturated transport regime characterized by nearly frequency-independent conductivity over the investigated frequency range. At higher MWCNT contents, a distinct resonance peak emerges at 3650 Hz, which remains invariant with both temperature and nanotube content. This resonance behavior is attributed to the formation of an effective LC network arising from the combined inductive and capacitive reactances within the interconnected MWCNT framework. Overall, these results demonstrate the highly tunable electrical properties of CNF-MWCNT nanocomposites and highlight their potential for applications in frequency-selective conductive materials.