Key words: supercritical water, supercritical hexane, carbon nanotubes, alumina, nanomaterials, composite materials
Nanosized composites based on multiwall carbon nanotubes (CNT) and Al2O3 are
obtained in the supercritical (SC) media (water, hexane, and their mixture). Materials
of the same net composition are obtained by hydrothermal synthesis and sol-gel method
for comparison. The composites were characterized by electron microscopy, X-ray
diffraction and thermal analysis. The structure of materials synthesized in SC media
depends on the fluid composition. The most uniform composite containing the alumina
particles with the size comparable to the diameter of the CNT and stabilized on the
carbon surface can be obtained using a SC mixture of hexane and water as a medium. If
water and hexane are used separately, the formation of large alumina crystals on the
CNT surface, or the contamination of the composite by the products of hexane pyrolysis
and carbonization are respectively observed.
doi:10.1134/S1990793116080157