چكيده به لاتين
Hydrogels are a type of three-dimensional network polymer that can be widely swollen in water and other solvents and are efficient in the adsorption process. Hydrogels are biocompatible materials and can be synthesized and modified by different methods. Also, the presence of nanoparticles and surfactants in their structure creates properties such as strength, crosslinking, magnetism and hydrophobicity. Most biomolecules, including bovine serum albumin (BSA) protein, have dual-purpose properties (hydrophilic and hydrophobic), and their selective adsorption is of particular importance. In this study, the synthesis of alginate-based magnetic hydrogels by sol-gel method was carried out by combining magnetic Fe3O4 nanoparticles with sodium alginate precursor and functionalizing it with different amounts of oleic acid surfactant by two synthesis methods. The presence of surfactant in the gel structure, due to its hydrophobicity, was effective in improving the properties of the hydrogel, including its hydrophobicity. The properties and structure of magnetic hydrogels were evaluated by different analyses, including contact angle, Raman spectroscopy, FT-IR, and zeta potential. The effect of four factors, the amount of oleic acid, temperature, pH, and the type of salts in the solution, on the amount of protein adsorption on magnetic hydrogels was investigated using a factorial experimental design at levels 4, 3, 3, and 3, respectively. The highest BSA adsorption capacity on magnetic hydrogels in buffer with pH = 3.5, presence of NaCl salt, temperature 35 ℃ and by hydrogel containing 0.15 g oleic acid (OA2,2) equal to 152.6 mg/g and close to 100% adsorption was achieved in 7 hours, which under these conditions, the highest hydrophobicity of the gels was achieved and also showed a suitable adsorption capacity compared to other adsorbents. The fitting of the adsorption data to kinetic models at different time points indicated that the adsorption was multi-stage with physical bonds and an endothermic process occurred. Desorption experiments also showed the appropriate resistance of the hydrogel in at least 3 consecutive adsorption-desorption cycles with a 12% decrease in adsorption capacity.
