Controlled-release technologies are considered a key solution to deliver both pheromones and pesticides for better environmental and economical benefits. Metal-organic frameworks (MOFs) have gained a certain success in this area to deliver drug molecules. In this study, three different zirconium-based MOFs with different linkers (benzene-1,4-dicarboxylate, 2-aminobenzene-1,4-dicarboxylate and 2-(propylamino)benzene-1,4-dicarboxylate) were synthesised via a solvothermal method and examined for their possible use in pheromone delivery. The powder X-ray diffraction (PXRD) and nuclear magnetic resonance (NMR) results showed that these MOFs were produced successfully. 3-octanone, an archetypal pheromone used in this study, was loaded into the MOFs and the loading examined by NMR spectroscopy, showing that these MOFs are capable of accommodating pheromones in different quantities. Physical properties (e.g. surface area, pore volume and crystal density), nitrogen adsorption and pheromone diffusion of MOFs were studied in depth using simulation methods. The higher electrostatic contribution of UiO-66-NH2 leads to higher guest-host interaction energies than UiO-66. These findings suggest a promising porous material for use in sustainable agriculture.
Figure. a) Simulated nitrogen isotherm of MOFs at 77 K (logarithmic pressure axis) generated from Monte Carlo simulation. b) Mean square displacement of 3-octanone in MOFs generated from Molecular Dynamics simulation