Biological, optical and electrical behaviour of k- carrageenan/PVA/TiO₂ nanocomposite film

In the present study, poly (vinyl alcohol) (PVA), kappa-Carrageenan (kC), kC/PVA polymer blend and kC/PVA nanocomposites incorporating varying concentrations of TiO₂ nanoparticles (1 %, 1.5 %, 2 %, and 2.5 % w/w) were successfully prepared and characterized for its electrical, optical and biological behaviour. The composite film was prepared using a solution casting method by incorporating titanium dioxide (TiO₂) nanoparticles into polymer matrix to enhance its multifunctional properties. The mechanical, structural, morphological, thermal, electrical and optical characteristics of the films were systematically analysed using various techniques. XRD analysis confirmed the effective incorporation of TiO₂ nanoparticles into the polymer matrix, resulting in improved crystallinity. FTIR spectra indicated strong chemical interactions between the polymer blend and nanoparticles, suggesting enhanced compatibility and uniform dispersion. The mechanical properties of the nanocomposite were notably improved with filler incorporation. UV-Visible spectroscopy revealed increased optical absorption upon nanoparticle addition, while a noticeable reduction in optical band gap pointed to enhanced optoelectronic characteristics. Electrical measurements showed a significant rise in AC conductivity, correlating with efficient charge transport due to well-dispersed nanoparticles. Dielectric studies supported these findings, showing enhanced dielectric behaviour at optimal nanoparticle concentration, demonstrating potential for energy-related applications. The nanocomposite film showed significant antimicrobial activity against both gram-negative (E. coli) and gram-positive (S. aureus) bacteria, along with enhanced wound healing behaviour, highlighting its potential as a promising material for biomedical applications. The synergistic effect of TiO₂ in kC/PVA matrix resulted in a polymer nanocomposite film with enhanced mechanical strength, AC conductivity, optical responsiveness and biological activity.