Surfactant double layer stabilized magnetic nanofluids for biomedical application

Area of Science:

• Materials Science
• Nanotechnology
• Colloid Science

Background:

• Water-based magnetic fluids (MFs) are crucial for various applications.
• Controlling nanoparticle aggregation is key to fluid stability.
• Surfactant coatings are essential for stabilizing magnetic nanoparticles in aqueous media.

Purpose of the Study:

• To investigate the impact of surfactant structure on magnetite nanoparticle stability in water-based magnetic fluids.
• To determine the optimal surfactant configurations for preventing particle aggregation.
• To evaluate the performance of these magnetic fluids under varying conditions for potential biomedical use.

Main Methods:

• Preparation of magnetite nanoparticles coated with surfactant double layers.
• Characterization using adsorption isotherms, dynamic light scattering (DLS), and electrophoretic mobility measurements.
• Assessment of fluid stability concerning dilution, pH, and salt concentration.

Main Results:

• Surfactant head group and alkyl chain length significantly influence fluid stability.
• Na-oleate adsorption confirmed double layer formation with a saturation value of 2 mmol g⁻¹.
• Oleic and myristic acid double layers provided excellent stability, preventing aggregation up to physiological salt concentrations (pH 6-8).

Conclusions:

• The combined steric and electrostatic stabilization from oleic and myristic acid double layers effectively prevents magnetite particle aggregation.
• These stable magnetic fluids demonstrate suitability for biomedical applications due to their performance in physiological conditions.
• Tailoring surfactant structures offers a viable strategy for designing advanced magnetic fluid systems.