Biodegradable Nanostructured Nerve Conductors: Electrical Properties And Adsorption Kinetic Models

Abstract

Model samples of nerve conductors with incorporated particles of inorganic origin: chitosan (CS), ZnO, Fullerene C60, dopped with Fe3+ ions multi-walled carbon nanotubes (MWCNTs+Fe) were successfully synthesized and investigated. The inclusion of inorganic particles in the alginate (Alg)-based composites reduces hydration (swelling) degree and affects the material’s resistance, leading to a decrease in the electrical conductivity. The MWCNTs+Fe-containing sample shows the highest electrical conductivity, mainly due to iron ions. ZnO and fullerene C60-containing samples have the lowest electrical conductivity due to high density and lower ability to hydrate. The mechanisms of Trp adsorption on the experimental samples were determined with Langmuir, Freundlich, Slips, and Henri isotherms equations. Sips isotherm model, which predicts the heterogeneity of the adsorption system, provides the best correlation of all experimental sample data, and the $\text{r}^{2}$ values of about 99% confirm that. The adsorption on the ZnO-containing sample is well fitted to the Freundlich isotherm model (1/n<1), which means that reversible and non-ideal adsorption is favorable. The heterogeneity of the Alg-ZnO surface, as well as the exponential distribution of the active energies sites, takes place.