Influence of cesium bromide nanoparticles on the structural, optical, electrical, and antibacterial properties of polyvinyl alcohol/sodium alginate for biological applications

Abstract

This study investigates the use of organic and inorganic nanostructures to create innovative functional materials with applications in optoelectronics devices. Specifically, nanocomposite films were created by incorporating different concentrations of cesium bromide nanoparticles (5, 10, and 15 wt%) into a polyvinyl alcohol (PVA) and sodium alginate (SA) polymer blend (50/50 wt%) through a solution casting process. The impact of CsBr NPs on the structural, optical, and electrical properties of the virgin PVA/SA matrix was systematically investigated. x-ray crystallography investigation verified the semicrystalline nature of the PVA/SA. FTIR spectra showed the main vibrational peaks of PVA/SA, with their intensity decreasing after the addition of cesium bromide. Scanning electron microscopy images showed the formation of aggregations and the increase of roughness for the PVA/SA-CsBr NPs 15 wt% nanocomposite sample. The UV/vis. absorption spectrum showed a decrease in the energy gap values, which decreased from 4.25 to 3.89 eV in the direct transition and decreased from 4.12 to 3.77 eV in the indirect transition. Furthermore, the electrical conductivity and dielectric properties demonstrated improvement with increasing concentration of CsBr NPs. The antibacterial efficacy against Staphylococcus aureus and Escherichia coli exhibited an upward trend with an increase in CsBr nanoparticle concentration. Overall, the results suggest the promising potential of these nanocomposite films for applications in optoelectronics and biological applications.

Highlights

• XRD shows that the amorphousity is increased after addition CsBr NPs.
• FT-IR confirms the interactions/complexation between PVA/SA polymeric matrix filled with CsBr NPs.
• Optical energy gap is decreased with increasing CsBr concentrations.
• SEM images show the prepared samples have a smooth surface and only have a few defects.
• By adding CsBr NPs the electrical conductivity is tremendously improved.