A study of optical properties of copper sulphate pentahydrate doped IOTA-carrageenan polymer electrolytes

Abstract

Biodegradable polymer films composed of Iota-Carrageenan and Copper Sulphate Pentahydrate (CuSO₄.5H₂O) were prepared by using the Solution Casting process. To investigate the optical property, different wt.% of CuSO₄.5H₂O were added to I-carrageenan polymer films. X-Ray diffraction analysis was used to study the structural properties of prepared electrolytes. FTIR study revealed the complexation between the polymer and the salt. The increase in the amorphous nature of the film by the addition of the salt was confirmed using an X-Ray Diffraction (XRD) pattern. The functional group and interaction between the different components present in the polymer film are observed from Fourier Transform Infrared (FTIR) analysis, implying that the addition of (CuSO₄.5H₂O) salt causes microstructural differences in the polymer film. The UV-Visible Spectrometer was used to record the optical properties like the absorption coefficient, extinction coefficient, and optical bandgap energy of the polymer blend electrolytes. From this, it was observed that the absorption value was increased with the addition of salt. The optical band gap was also recorded and it was observed that 20 wt.% of CuSO₄.5H₂O added film was found to have a higher energy gap (4.3 eV) compared with the other.