Formation of PVA-SiO 2 hybrid films by Sol-Gel method: Effect of processing parameters and SiO 2 content on the structure and physico-chemical properties

In light of their unique properties and potential applications silicon dioxide (SiO ₂ ) and polyvinyl alcohol (PVA) nanocomposites synthetized through the method known as sol-gel is gaining interest. For the first time, we investigated studied how processing variables like the number of HCl drops and the drying temperature influenced gel setting time. In the second time, tetraethoxysilane (TEOS) was hydrolysed and then condensed in a poly(vinyl alcohol) (PVA) solution to create organic–inorganic hybrid materials (PVA/SiO ₂ ). With varying SiO ₂ contents, the hybrid's optical properties and structure have been studied using infrared (FTIR) spectroscopy. For the hybrid, which includes 16% of SiO ₂ , the thermal characteristics were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Si–O–C and Si–O–Si bond formation in the system was demonstrated using FTIR spectroscopy. TGA and DSC analysis showed that the hybrid films had better thermal stability and a lower melting temperature when compared to neat PVA films. At 190°C, PVA shows an intense endothermic peak, which indicates the melting point. Compared to neat PVA, the PVA/SiO ₂ shows a less severe melting endothermic peak which is very weak and broad, discovered around 165°C. This suggests a decrease of 25°C. The hybrid film was also rendered more resistant to water absorption.