Effect of pH and temperature on the release kinetics of urea from wheat-gluten membranes obtained by electrospinning

Optimal usage of urea-based fertilizers can increase their use efficiency and reduce pollution. A new alternative for prolonged-release (PR) urea based on wheat-gluten (WG) membranes obtained by electrospinning was studied. The effect of pH and temperature on the release rate of urea and its transport mechanisms were evaluated. At pH 4, 7, and 10, the equilibration times obtained were 1, 3, and 5 h, respectively. Additionally, at a higher temperature, a larger amount of urea was released into the medium. The Ritger–Peppas model suggests that with pH 4 and pH 10, at 25 °C, there is an anomalous diffusion mechanism. On the other hand, the remainder of the release conditions tested showed a release mechanism of urea by simple diffusion. According to the results, a potential application of these wheat-gluten membranes on the release system of urea for soils with pH 7 and soil temperatures between 25 and 40 °C is proposed.