CHEMICAL ENGINEERING TRANSACTIONS
VOL. 43, 2015
A publication of
The Italian Association
of Chemical Engineering
Online at www.aidic.it/cet
Chief Editors: Sauro Pierucci, Jiří J. Klemeš
Copyright © 2015, AIDIC Servizi S.r.l.,
I SBN 978-88-95608-34-1; I SSN 2283-9216
Calcium Phosphate Composites and Silica Obtained from the
Rice Hull for Biomedical use. Synthesis and Characterization
Nerly D. Montañez*
,a
, Dario Y. Peña
b
a
Universidad Manuela Beltrán, Bucaramanga, Colombia. Calle de los estudiantes No. 10-20 Cuidadela real de minas
b
Universidad Industrial de Santander, Bucaramanga, Colombia. Calle 27, carrera 9 Ciudad universitaria
ing.nerly.montanez@hotmail.com
This paper describes the development of composites of calcium phosphate and silica, wherein the silica is
obtained from rice husk as a natural source. The objective was to develop calcium phosphate composites and
silica that meet physical and chemical characteristics for potential applications in bone treatments as synthetic
filler and assess their degradation in simulated physiological fluid. Carried out the synthesis of each of the
materials and the physicochemical characterization of each composite and formed by means of analysis by X-
ray diffraction (XRD) and scanning electron microscopy (SEM), degradation tests were carried out with the
material. The composite was developed using metallurgy of powders of calcium phosphate and silica. The
results showed that the calcium phosphate composite and silica obtained from rice hush can be used as
synthetic bone filling material with the synthetic connotation variant.
1. Introduction
Rice hulls, RH for its acronym in English (Rice Husk), is one of the main agricultural products obtained from
rice production in countries like China, India, Indonesia, Bangladesh, Viet Nam, Thailand, Japan, Myanmar,
Philippines Brazil and others (Rojas, 2014). In rice producing countries, occurs around 20 – 25 % by weight of
rice husk, which in 2007 was between 123 and 132 Mt (Xiong et al., 2009).
Rice hulls has a high silicon content, existing as hydrated silicon (Prakash, 2010) and additionally contains
potassium (K), aluminum (Al), phosphorus (P), iron (Fe), manganese (Mn) and chlorine (Cl) (Forero et al.,
2009). Its structure is porous, allowing moisture absorption. The chemical compositions of RH vary from one
sample to another, related to the type of rice crop year, climatic variations, geographical conditions, and even
the fertilizers used in growing rice (Chandrasekhar, 2003). The scale chemical analysis suggests that rice
husk consist to about 22 % of silica or silicon oxide (SiO2) (Farook et al., 2003), to about 74% of water and
organic matter, and to about 4% of Al2O3 + CaO + MgO + Fe2O3, (Kumar et al., 2012) and to about 4 % Al2O3
+ CaO + MgO + Fe2O3 (Prasad-Pandey, 2012). The percentage of SiO2 varies between 15 % and 22 % and is
in hydrated form (Chandrasekhar, 2003).
Silica is an element that constitutes our skeletal system, and is involved in the synthesis of collagen content in
bone and connective tissue, as well as favorably involved in the reconstruction of destroyed cartilage in the
case of joint disease. Silica is one of the base substances of biomaterials called bioglasses, which also
contain sodium, potassium, magnesium, calcium and phosphorus. Bioglasses have been used in medical
applications such as controlled drug delivery systems, implants without much charging cradle and bone
cements (Lopez et al., 2013). Bioglass has performed well in terms of compatibility in vitro assays with
osteoblast-like cells, resulting in the formation of surface apatites bioglass in (Oudadesse et al., 2011).
Hydroxyapatite comprises crystalline calcium phosphate (Ca10(PO4)6(OH)2) and represents a tank body of 99
% calcium and 80 % of total phosphorus (Wang et al., 2003). The use of implants covered hydroxyapatite or
tricalcium phosphate has been widely described for demonstrating an early attachment between them and the
surface of the bone, about one month after insertion. It was also shown that the anatomy of the soft tissue
around the implant is normal and there is no inflammation (Sato et al., 2005). Hydroxyapatite (HAp), obtained
from natural sources or synthetic sources, is considered a bioactive substance that forms strong chemical
DOI: 10.3303/CET1543290
Please cite this article as: Montanez Supelano N.D., Pena Ballesteros D.Y., 2015, Calcium phosphate composites and silica obtained from the
rice hull for biomedical use. synthesis and characterization, Chemical Engineering Transactions, 43, 1735-1740 DOI: 10.3303/CET1543290
1735