Preparation Mechanism and Application of Alcohol-modified Fe3O4 Magnetic Nanoparticles

Herein, modified Fe3O4 particles (named as E-Fe3O4, P-Fe3O4 and D-Fe3O4, respectively) were prepared by chemical precipitation method using ethyleneglycol (EG), polyethylene glycol (PEG) and mannitoll (D-M) as the separated modifier. The results showed that the alcohol molecules can be successfully modified on the surface of Fe3O4 particles, and the morphology, size, crystal phase and magnetic properties of Fe3O4 particles are not significantly affected. Modification mechanisms of Fe3O4 samples are studied by Fourier transform infrared spectroscopy, ion selective electrode method, Zeta potential and water contact angle tests. It is shown that the modification mechanism of P-Fe3O4 and D-Fe3O4 samples are associated with the hydrogen bonding of water molecules mediated, while more stable hydrogen bond can be formed between ethylene glycol and hydroxyl group on the surface of E-Fe3O4. Consequently, ethylene glycol was still fixed on the surface of Fe3O4 even under high temperature treatment (120 degrees C). E-Fe3O4 with hydrophobic group on the surface exhibits optimal hydrophilicity (contact angle was 32.92 degrees) and water dispersion behavior (diameter was about 200-300 nm). E-Fe3O4 with negative surface charge can be applied to remove cationic dye crystal violet (CV) from water and adsorption capacity was 19.33 mg/g, which was 2.3 times of that pristine Fe3O4 (8.41 mg/g). Besides, the addition of isopropanol is beneficial for CV desorption. This study not only provides a new method for preparing magnetic nano-Fe3O4 adsorption material, but also provides a theoretical basis for its application in the separation and adsorption of dye wastewater.

Automated summary

Through modified treatment, magnetic nano-Fe3O4 adsorption materials were successfully prepared, with different modifiers impacting their properties. The introduction of hydrophobic groups resulted in excellent hydrophilicity and water dispersibility of Fe3O4 particles. Additionally, the modified Fe3O4 showed a higher adsorption capacity for cationic dye crystal violet, making it suitable for dye wastewater treatment.