Abstracts Book - IMRC 2018

• SB2-O011
EFFECT OF THE CRYSTAL SIZE ON THE X-RAY DIFFRACTION OF
BIO-HYDROXYAPATITE
Mario Enrique Rodríguez García 1 , Rodrigo Jeronimo Cruz 2 , Batriz Marcela Millán Malo 1 , Eric M.
Rivera Muñoz 1 , Sandra Milena Londoño Restrepo 1
1
Universidad Nacional Autónoma de México, Nanotecnología, Mexico. 2 Universidad Nacional
Autónoma de México, Licenciatura en Tecnología, Mexico.
This work focuses on the effect of the hydroxyapatite crystal size on the X-ray
diffraction pattern. Bio-hydroxyapatite (BIO-HAp) was obtained three sources:
bovine, porcine, and human. Samples were milled and then cleaning by defatting
using petroleum ether, and deproteinized using calcium hydroxide 0.005M, and
sodium hypochlorite 13% (v/v). Vibrational properties were determined by Infrared
and Raman spectroscopy that showed that there was only the inorganic phase
which confirms the removal of the organic phase. Inductively Couple Plasma (ICP)
showed the presence of Mg, K, S, Ba, Zn, Na, among others. Through X-ray
diffraction, broad peaks for hydroxyapatite were obtained for all samples. A low
crystalline quality has been reported for hydroxyapatite obtained biogenic sources
as it is the case of mammalian bones, but the broad peaks showed in their patterns
could be originated by the scattering produced by hydroxyapatite nanocrystals. In
fact, the nanocrystals were observed by High-Resolution Scanning Electron
Microscopy, which was about 7 to 10 nm. TEM was used to determine the crystal
size, the crystalline quality; the first value was used for the simulation of the X-ray
diffraction pattern of all bio-HAp. Our results showed that the X-ray diffraction
patterns of these HAps are governed by the scattering and correspond to the
nanocrystal size that also is confirmed by the broad peaks in all studied cases. These
results suggest that the calculations of the crystalline quality cannot be done if the
crystal size is less than 60 nm.
Acknowledgment: S. M. Londoño-Restrepo thanks the Consejo Nacional de
Ciencia y Tecnologıa (CONACYT-Mexico) for the financial support of her Ph.D.
thesis, and PAPIIT project number IN112317 for the financial support of this
investigation as well. The authors would like to thank Dra. Antonieta
Mondragón-Sosa for her technical support for the Raman experiments, M.
Alicia del Real for technical support, and Carolina Muñoz CGEO-UNAM for the
ICP determinations.
Keywords: Hydroxyapatite, nanocrystals, crystalline quality
Presenting authors email: marioga@fata.unam.mx