2. International Scientific Research Congress, Iğdır, Türkiye, 26 - 27 Eylül 2023, ss.524-533, (Tam Metin Bildiri)
With the rapid development of electronic technology and energy conversion from
renewable sources, the interest in polymer composites, which are different from traditional
materials and can have adjustable optical and electrical properties, is gradually increasing.
Additionally, considering environmental concerns, the preference for low-cost,
sustainable, and biodegradable polymers is of great importance. To achieve this goal, in
recent years, the approach of blending biopolymers with synthetic polymers has been
pursued. Adding carbon fillers such as nano-scale diamond, graphite, fullerene, graphene,
carbon black, and carbon nanotubes to polymer blends is a common strategy used to
obtain materials with desired properties.
In this study, Polyvinyl Alcohol / Chitosan (PVA / CS) biocomposite films containing
multi-walled carbon nanotubes (MWCNTs) at different ratios (0, 5, 10, 15, 20, 25 wt.%)
were prepared using ultrasonication-assisted solution mixing and spin-coating methods.
The changes in the structural, electrical, and optical properties of the obtained
biocomposite films were investigated. The observed behaviors in the electrical and optical
properties of PVA/CS biocomposite films were interpreted using both percolation
theories, namely, the site and classical percolation theories. The electrical and optical
percolation thresholds were determined to be Rσ = Rop = 2.5 wt.%. The critical exponents
for electrical (βσ) and optical (βop) percolation were calculated as 2.85 and 0.45,
respectively. The electrical conductivity of pure PVA/CS blend was found to be 6.0 x 10-
13 S/cm. With an increase in the content of MWCNTs in the composites, the electrical
conductivity value reached 9.8 S/cm. This result indicates a transition from an insulating
state to a conducting state. The significant improvements in the electrical and optical
properties of PVA/CS biocomposites hold promise for their use in various industrial
applications.