Synthesis and characterization of a novel hybrid film based on polyvinyl chloride/modified clays/photosensitizers: application to pollutants photo-degradation

The present study aims to synthesize a hybrid thin film with sol–gel process via dip-coating and spin-coating techniques. Prepared films are used in the elimination several pollutants using the photodegradation process. Used films are prepared by mixing polyvinyl chloride (PVC)/hydro-phobic-modified clays (Hc). First, we modified natural bentonite (Bt) and sodium montmorillonite (Na-Mt) with a surfactant cetyltrimethylammonium bromide. incorporation of methylene blue (MB) as photosensitizers into Hc was realised with different percentage of hydrophobic clay/photosensitizers at ambient temperature and optimum pH for 3 h. Secondly, the PVC/modified clay thin films were elaborated with sol–gel technology, using two techniques for deposition: Dip-coating in dimethylformamide and spin-coating in tetrahydrofuran. We modified some parameters such as weight ratio polymer/modified clay, number of dipper, rotational velocity, viscosity of polymer solution, rotation time and ramping –up rate for optimum conditions. Prepared films are characterized by X-ray diffraction, scanning electron microscopy-X-ray fluorescence and Fourier-transform infrared spectroscopy, the obtained results show the good insertion of MB into different support. The deposition on PVC increase the distance basal of materials. The efficiency of our prepared films was evaluated through the degradation of some dyes such as tartrazine (TR) and methyl orange (MO), using photoreactor upon irradiation with visible light and air injection. The obtained results show a significant efficiency of the films in the degradation of MO and TR. The TR degradation yields obtained vary from 72% to 76% for films containing 5% MB, and a yield close to 99% for the degradation of MO.