NANO EXPRESS
Surface Modification and Planar Defects of Calcium Carbonates by Magnetic Water Treatment
1 Department of Materials and Optoelectronic Science, National Sun Yat-sen University, Kaohsiung, Taiwan, R.O.C
2 China Steel Incorporation, T64, Kaohsiung, Taiwan, R.O.C
Nanoscale Research Letters 2010, 5:1982-1991 doi:10.1007/s11671-010-9736-5
Published: 18 August 2010Abstract
Powdery calcium carbonates, predominantly calcite and aragonite, with planar defects
and cation–anion mixed surfaces as deposited on low-carbon steel by magnetic water
treatment (MWT) were characterized by X-ray diffraction, electron microscopy, and
vibration spectroscopy. Calcite were found to form faceted nanoparticles having 3x
(
) commensurate superstructure and with well-developed {
} and {
} surfaces to exhibit preferred orientations. Aragonite occurred as laths having 3x
(
) commensurate superstructure and with well-developed (
) surface extending along [100] direction up to micrometers in length. The (hkil)-specific
coalescence of calcite and rapid lath growth of aragonite under the combined effects
of Lorentz force and a precondensation event account for a beneficial larger particulate/colony
size for the removal of the carbonate scale from the steel substrate. The coexisting
magnetite particles have well-developed {011} surfaces regardless of MWT.
