Synthesis, characterizations and kinetics of MOF‐5 as herbicide vehicle and its controlled release in PVA/ST biodegradable composite membranes

Abstract

AbstractPolyvinyl alcohol/starch based composite membranes containing herbicide‐loaded metal‐organic‐framework (MOF‐5) was successfully synthesized by electrostatic spraying technique. Several main parameters affecting the adsorption of MOF‐5 were studied, including the initial concentration of the herbicide solution, adsorption time, and temperature. Under optimal conditions, herbicide‐loaded MOF‐5 was successfully synthesized and the main properties were characterized by Scanning Electron Microscopy (SEM), X‐Ray Diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric Analysis (TG), and Brunauer‐Emmett‐Teller (BET), respectively. The results showed that the adsorption capacity of MOF‐5 at optimal conditions was 60.12wt%±0.61 % for atrazine. The sustained release effect of the AT@MOF‐5/PVA/ST composite membranes was reliable, and the cumulative release rate was about 50 % for 15 h. The release behaviour of AT from AT@MOF‐5/PVA/ST composite membranes was first dominated by the mechanism of Fickian diffusion and then by the mechanism of matrix erosion. The main advantages of agricultural herbicide film can be attributed to the eco‐friendly, biodegradable, and persistence of herbicide.