Open Access NANO EXPRESS

Surface Modification and Planar Defects of Calcium Carbonates by Magnetic Water Treatment

CZ Liu1, CH Lin1, MS Yeh2, YM Chao2 and P Shen1*

Author Affiliations

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

For all author emails, please log on.

Nanoscale Research Letters 2010, 5:1982-1991  doi:10.1007/s11671-010-9736-5

Published: 18 August 2010

Abstract

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.

Keywords:
Calcium carbonate; Nanoparticle; Magnetic water treatment; Surface modification; Superstructure; TEM