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We prepared poly(vinyl alcohol) (PVA)/SiO 2 and PVA/SiO 2 /glutaraldehyde (GA) nanocomposite membranes in a single step using the solution casting method. The structure, morphology, and properties of these nanocomposite membranes were characterized by Raman spectroscopy, atomic force microscopy, small-and wideangle X-ray scattering, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis (DMA). The influence of silica and GA loading on the meso-scale characteristics of the composite membranes was investigated. The results showed that silica deposited in the form of small nanoparticles (*1 nm) in the PVA/ SiO 2 membranes, while bigger submicron particles ([25 nm) were formed in the PVA/SiO 2 /GA membranes. The water uptake of the PVA/SiO 2 membranes increased with temperature, but the PVA/SiO 2 /GA membranes were completely dissolved above 50°C. We can therefore conclude that the addition of GA deteriorated the properties of PVA/SiO 2 membranes. The thermal stability of the PVA/ SiO 2 membranes increased with the increasing silica loading with a maximum char yield of 46 % for PVA/SiO 2 / 4T. Even DMA profiles indicated a promising increase in E R (rubbery modulus) from 6 MPa (PVA membrane) to 1015 MPa (PVA/SiO 2 /4T) at 250°C, showing high mechanical strength of these membranes.

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In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.