Study of sorption properties of zirconia, alumina, and silica in relation to repellents

In this work, the morphology of zirconia, alumina, and silicas was studied, and static sorption of the repellents N, N-diethyl-3-methylbenzamide and ethyl-3-[acetyl(butyl)amino]propionate on these oxides was carried out. ZrO₂, Al₂O₃, and SiO₂ phenyl were shown to have high sorption activity to the repellents N, N-diethyl-3-methylbenzamide (239 mg/g for SiO₂ phenyl) and ethyl-3-[acetyl(butyl)amino]propionate (251 mg/g for ZrO₂). Pointedly, it was found that despite having the largest pore volume and high specific surface area (compared to the other studied oxides), SiO₂ C2 has a significantly inferior sorption capacity in respect to other oxides, in particular SiO₂ phenyl, which can be explained by the presence of the phenyl group in the latter that has chemical affinity for repellent molecules. Obtained isotherms of SiO₂ 300 also confirm the low sorption activity towards N, N-diethyl-3-methylbenzamide. The sorption equilibrium for both repellents, in most cases, is described by the Langmuir monomolecular adsorption model. The obtained results suggest that the studied zirconia, alumina, and silica can be used as carrier components of repellents.