Effect of Wet and Dry Environments in CNC/MWCNTs/Ag2O Electrically Conductive Films: Material Characterization and Molecular Dynamics Simulation

Electrically-conducting biobased materials present a bright future to be used in high-technological applications including sensors, soft electronics and active packaging. Accordingly, in this work we develop and characterize ternary nanohybrid films combining cellulose nanocrystals (CNC), multi-walled carbon nanotubes (MWCNTs) and silver oxide (Ag2O) nanoparticles. An evaporation-induced self-assembly process is applied to obtain homogenously dispersed free-standing nanocomposite films as proven by electron microscopy observations. Thermogravimetric analyses show that while MWCNTs delay the cleavage of glycosidic linkages of cellulose, Ag2O catalyzed thermodegradation events to render materials with reduced thermal stabilities. The electrical and dielectrical properties of the nanohybrid materials are analysed under completely dry and 53% humidity atmospheres and the results are observed also in the light of the electric modulus. Water increases the conductivity of binary and ternary systems and shift the electric modulus relaxation peak. Finally, full atom molecular dynamics simulations are performed for the first time to better describe the phenomena on interfaces between nanoscale systems, underlying mechanisms for the obtained electrical AC and DC results. Computational results reveal changes in the CNC/MWCNT/Ag2O interactions depending on the water presence, more different types of interactions are found in relation to the type of nanomaterial. The combination of experimental and simulation data here shown sheds further light on the electric conducting mechanism of nanocellulose-based materials with multifunctional properties.