Structural, Optical, and Electrical Parameters of Doped PVA/PVP Blend with TPAI or THAI Salt
A M El-Naggar1, Shadia Z Brnawi2, A M Kamal2
1Research Chair of Exploitation of Renewable Energy Applications in Saudi Arabia, Physics & Astronomy Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
Polymers
|June 28, 2023
Summary
Polymer blends of polyvinyl alcohol/polyvinyl pyrrolidone doped with tetrapropylammonium iodide or tetrahexylammonium iodide salts show enhanced UV shielding properties. These materials exhibit reduced optical bandgaps and high refractive indices, making them suitable for UV protection applications.
Area of Science:
- Materials Science
- Polymer Chemistry
- Optoelectronics
Background:
- Polymer blends offer tunable properties for advanced applications.
- Quaternary ammonium salts can modify polymer characteristics.
- Understanding salt-polymer interactions is crucial for material design.
Purpose of the Study:
- To prepare and characterize PVA/PVP polymer blends doped with TPAI and THAI salts.
- To investigate the influence of salt type and concentration on optical and electrical properties.
- To evaluate the potential of these blends as UV shielding materials.
Main Methods:
- Polymer blend preparation using DMSO solvent.
- X-ray diffraction (XRD) for crystallinity analysis.
- Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) for morphology and composition.
- Fourier Transform Infrared Spectroscopy (FTIR) for chemical analysis.
- UV-Vis spectroscopy for optical properties (absorbance, reflectance, bandgap).
- Refractive index and DC conductivity measurements.
Main Results:
- Enhanced UV absorbance and reflectance observed, peaking at 24% TPAI or THAI doping, indicating suitability for UVA/UVB shielding.
- Optical bandgaps significantly reduced from initial values (direct: 5.1 eV, indirect: 4.8 eV) to around 3.5 eV with increasing salt content.
- The blend with 24% wt TPAI showed the highest refractive index (~3.5 in the 400-800 nm range).
- DC conductivity varied with salt content, type, dispersion, and blend-salt interactions, with activation energies determined via the Arrhenius formula.
Conclusions:
- PVA/PVP blends doped with TPAI and THAI salts exhibit promising optical properties for UV shielding applications.
- Salt doping effectively modifies the optical bandgap and refractive index of the polymer blends.
- The study provides insights into structure-property relationships for salt-doped polymer systems.
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