Formulation and characterization of crosslinked polyvinyl alcohol (PVA) membranes: effects of the crosslinking agents

The article addresses the formulation and characterization of the polyvinyl alcohol membrane (PVA) with citric acid, succinic acid and their mixing as crosslinking agents. PVA is highly hydrophilic and has excellent film (membrane) properties. Chemical crosslinking is the most common approach to stabilize and produce PVA membranes with enhanced mechanical resistance. Thus, we prepared membranes with variable PVA and crosslinking agents. The thermal properties of the membranes were analyzed using thermogravimetric method (TGA), while the functional groups formed in the membrane were determined using Fourier-transform infrared spectroscopy. The water absorption of the membranes was determined by the degree of swelling. The oxidative stability was obtained using the Fenton test. The ion exchange capacity was also evaluated. Membrane structure, morphology and surface properties were analyzed by topography and adhesion force using atomic force microscopy. The scanning electron microscopy was used to elucidate the fractures. The results indicated that the membranes exhibited roughness uniformly distributed, indicating homogeneous films and excellent crosslinking features allied to enhanced adhesion and strength properties with good stability.