Augmentation of chain formation in a magnetic fluid by the addition of halloysite nanotubes

作者：Desai Rucha^*; Upadhyay R V; Mehta R V

来源：Journal of Physics D: Applied Physics , 2014, 47(16): 165501.

DOI：10.1088/0022-3727/47/16/165501

• magnetic liquids
• nanotubes
• magnetization dynamics
• magneto-optical effects
• dynamics of magnetic nanoparticles

The study aims to investigate the effect of the addition of nanotubes of halloysite on the augmentation of chains observed in an aqueous magnetic fluid consisting of co-precipitated magnetite particles stabilized with lauric acid. Three samples of the mixture containing 0.5%, 1% and 2% of halloysite nanotubes (HNTs) and a pure magnetic fluid are used for this study. A room temperature magnetization study shows that for 0.5% and 1% of HNT, the magnetization of the mixture significantly increases, while for the higher concentration (2%) it decreases. Such concentration dependent behaviour on the addition of a nonmagnetic system to a magnetic fluid has not previously been observed. The increase in the magnetization is attributed to smaller sized (<5-6 nm) magnetite attached to the HNT, forming a magnetite-HNT composite. Additionally, field-induced chaining is augmented by the addition of HNT in the magnetic fluid. The augmentation of chain formation is confirmed by optical microscopy, field-induced transmission changes and field-dependent diffraction effects. The augmentation will be useful in enhancing other properties of the composite, such as the viscosity and thermal conductivity of nanofluids.

• 出版日期2014-4-25