Thumbnail
Access Restriction
Open

Author Madupalli, Honey ♦ Pavan, Barbara ♦ Tecklenburg, Mary M. J.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY ♦ APATITES ♦ CARBONATES ♦ CRYSTALS ♦ FOURIER TRANSFORM SPECTROMETERS ♦ INFRARED SPECTRA ♦ SKELETON ♦ TEMPERATURE RANGE 0065-0273 K ♦ TEMPERATURE RANGE 0400-1000 K ♦ X-RAY DIFFRACTION
Abstract The mineral component of bone and other biological calcifications is primarily a carbonate substituted calcium apatite. Integration of carbonate into two sites, substitution for phosphate (B-type carbonate) and substitution for hydroxide (A-type carbonate), influences the crystal properties which relate to the functional properties of bone. In the present work, a series of AB-type carbonated apatites (AB-CAp) having varying A-type and B-type carbonate weight fractions were prepared and analyzed by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and carbonate analysis. A detailed characterization of A-site and B-site carbonate assignment in the FTIR ν{sub 3} region is proposed. The mass fractions of carbonate in A-site and B-site of AB-CAp correlate differently with crystal axis length and crystallite domain size. In this series of samples reduction in crystal domain size correlates only with A-type carbonate which indicates that carbonate in the A-site is more disruptive to the apatite structure than carbonate in the B-site. High temperature methods were required to produce significant A-type carbonation of apatite, indicating a higher energy barrier for the formation of A-type carbonate than for B-type carbonate. This is consistent with the dominance of B-type carbonate substitution in low temperature synthetic and biological apatites. - Graphical abstract: A series of differently substituted high temperature AB-type carbonated apatites show interesting structural changes, an additional B-carbonate site with the presence of A-carbonate in the apatite, and crystal domain sizes that correlate only with the amount of A-site carbonate. Our results provide an explanation for the dominance of B-type carbonate in biominerals. Display Omitted - Highlights: • Series of AB-type carbonated apatites with varying carbonate levels synthesized. • FTIR indicates additional orientations for B-site CO{sub 3}{sup 2-} with A-type substitution. • Crystal domain lengths correlate only to A-site CO{sub 3}{sup 2-} in high-temp AB-apatites.
ISSN 00224596
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-11-15
Publisher Place United States
Journal Journal of Solid State Chemistry
Volume Number 255


Open content in new tab

   Open content in new tab