Preparation and characterization of proton exchange polyvinylidene fluoride membranes incorporated with sulfonated mesoporous carbon/SPEEK nanocomposite

Synthesis of a Nitrile- and Ether-Rich Covalent Organic Framework as a Filler and Its Application for Proton Exchange Membranes

In the fabrication of proton exchange membranes (PEMs), incorporating nanomaterials into the polymer matrix is a promising strategy for enhancing membrane stability. However, this approach often results in a trade-off with proton conductivity. To address this limitation and develop efficient additives, we synthesized a novel covalent organic framework with a high density of ether and nitrile groups (COF-EN) via nucleophilic substitution as a nanofiller. This nanofiller was specifically designed to enhance both the proton conductivity and the stability of the membranes. The chemical structure of the synthesized COF-EN was confirmed through various analytical techniques, and it was subsequently integrated into a sulfonated poly(ether ether ketone) (SPEEK) matrix to fabricate advanced composite membranes. The resulting membranes demonstrated enhanced dimensional, thermal, and oxidative stability due to strong intermolecular interactions between the SPEEK chains and COF-EN. Additionally, the polar nitrile and ether groups in the COF-EN facilitated water absorption in the membranes, contributing to improved proton conductivity. As a result, SPEEK/COF-EN_3 exhibited a 2.3-fold increase in power density compared to the pristine SPEEK membrane, establishing COF-EN as an effective nanofiller for PEM fabrication.

GO-CuO nanocomposites assimilated into CA-PES polymer membrane in adsorptive removal of organic dyes from wastewater

Textile industries are one of the leading environmental pollutants by releasing harmful dye effluents. In many textile distrts, the amount of excess color in treated textile effluent that exceeds regulatory limitations is still being a major concern. The combining usage of nanomaterials and polymer material to solve these issues using various techniques. In this research, graphene oxide-copper oxide (GO-CuO) nanomaterial have been incorporated into cellulose-acetate (CA), poly-ether sulfone (PES) blend polymer by using phase inversion process to fabricate thin film nanocomposite (TFN) membrane for removal of dye pollutant. The physiochemical properties of prepared TFN materials were studied by Fourier transform infra-red spectroscopy (FT-IR), X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), thermo gravimetric analysis (TGA), and mechanical strength analysis. Dye adsorption experiments were performed with four typical water-soluble organic dyes methylene blue (MB), rhodamine blue (Rh. B), methyl orange (MO) and Congo red (CR). After reaching adsorption equilibrium, the composite membrane final removal effectiveness for MB 92.42%, Rh. B 89.39%, CR 68.39%, and MO 58.82% respectively. As a result, the fabricated TFN material proves to be an effective adsorbent material for cationic dye molecules. Also, when the fabricated material was tested with textile industry effluent sample, all physio-chemical properties exhibited a considerable decrease in concentrations when compared to the real textile effluent concentration. The treated effluents permitted for a relatively greater growth and germination index of Tropical amaranth roots than the textile effluent, this demonstrates that phytotoxicity testing was also successful. The most effective temperature, concentration and pH were found to be 273 K, 1 × 10^-5 M and pH 9. The fabricated TFN membrane material (GO-CuO @ CA-PES) can be recommended for water treatment applications.