Physical and Chemical Properties of the Surface of Aluminosilicate Halloysite Nanotubes Modified by Magnetite Nanoparticles

Halloysite is modified with magnetite nanoparticles by the chemical coprecipitation of iron salts. To characterize the surface and study the physical-chemical properties of the resulting composite and its components (halloysite and magnetite), we use dynamic light scattering, electron microscopy, the low-temperature adsorption–desorption of nitrogen, X-ray diffraction analysis, Mössbauer and IR (infrared) spectroscopy, and magnetic measurements. Energy-dispersive analysis data and X-ray diffraction patterns confirm the modification of halloysite by magnetite nanoparticles, changing the zeta potential and the adsorption capacity of the surface. IR spectral analysis of the studied composites reveal shifts in the characteristic bands of halloysite and magnetite during their formation. The halloysite/magnetite composite samples have a higher field strength of effective anisotropy and coercive force compared to magnetite.