Effect of functionalization on the electrochemical behavior of multi-walled carbon nanotube and parafilm nanocomposites

Soft, flexible and conductive interfaces are in high demand in wearable electronics where it can be used as electrode material integrated with commercial electronic components and living system. In the present study, we have developed flexible nanocomposites of multi-walled carbon nanotubes (MWCNTs) with parafilm (PF) thermoplastic. As the presence of carboxylic functionalization (COOH groups) at MWCNT surface improves their dispersion properties, pristine MWCNTs (p-MWCNT) were oxidized to produce functionalized multi-walled carbon nanotubes (f-MWCNT) and it was further used as conductive filler. Characterization and comparison of morphological, physical, chemical and electrochemical properties of p-MWCNT, f-MWCNT, p-MWCNT-PF nanocomposite film and f-MWCNT-PF nanocomposite film was done using SEM, FTIR, RAMAN spectroscopy, TGA and electrochemical studies. The results suggest that chemical oxidation of p-MWCNT majorly generates carboxylic functions at the p-MWCNT surface which decreases as f-MWCNT embeds in the PF matrix. The f-MWCNT-PF nanocomposite films are thermally more stable as compared to p-MWCNT-PF nanocomposite films. Chemical oxidation treatment generates graphitic defects facilitating electron transfer process and higher conductivity at the f-MWCNT-PF nanocomposite film electrode surface. We believe that the comprehensive performance of soft and flexible f-MWCNT-PF nanocomposite films offers a unique and effective way to develop electrochemical platform for biosensor fabrication in wearable applications.