Abstract
Vitamin E that contains α, β, γ, and δ-tocopherols and their tocotrienols is a fat-soluble vitamin with antioxidant properties. Adsorption of α-tocopherol is performed for various purposes, such as its purification from a product with different sorbents. We studied the adsorption of α-tocopherol onto silica. Firstly, hydrothermal temperature, hydrothermal time, and calcination time were optimized for silica synthesis according to the Taguchi design L9 orthogonal array. HT temperature 120 °C, HT time 72 hours, and calcination time 6 hours were determined for the best adsorption. Under these conditions, silica synthesis was carried out with ionic (CTAB and SDS) and non-ionic (P123) surfactants. Adsorption data were evaluated using Langmuir, Freundlich, and Temkin adsorption isotherm models and data fit the Langmuir model better. Maximum adsorption capacities were determined to be 153.85 mg/g for CTAB, 133.33 mg/g for P123, and 111.11 mg/g for SDS according to the Langmuir model. The synthesized materials were also characterized by SEM, FT-IR, XRD, and N2 adsorption/desorption methods. Although no statistically significant difference was found between the silica and silicas that synthesized with surfactants, the α-tocopherol adsorption capacity of silicas synthesized with CTAB was found to be higher than that of the other surfactants. The molecular structure of the surfactant used during synthesis changes the surface of the last material and the adsorption capacity of molecules. It has been observed that the use of a surfactant increases the BET surface area.