Page 324 - 00. Complete Version - Progress Report IPEN 2014-2016

324 Materials and Nanotechnology | Progress Report

Figure 45: TEM micrographies of Mg:β-TCP (A) as-synthesized and (B) after thermal treatment at 1000ºC for 30 seconds.

Nanotechnology 574m2/g) (Figure 45).

Novel fluorescent, crystalline These special nanoparticles become fluores-
and mesoporous beta tricalcium cent when doped with Europium ions. The
phosphate nanoparticles Eu/Mg:ο-TCP has an efficient visible lumines-

cence and constitutes a new nanoprobe that
Synthetic calcium phosphates, especially hy- can be used as optical contrast agents, afford-
droxyapatite (Ca10(PO4)6(OH)2) and beta-tri- ing high resolution and sensitivity for biomed-
calcium phosphate (Ca3(PO4)2), are of special ical applications.
interest in medicine because of their biocom-
patibility, bioactivity, non-cytotoxicity and
their similarity with human bone and teeth.
Due to their excellent biological functions and
responses in physiological environments, par-
ticular attention has been placed to ο–tricalci-
um phosphate, which has being widely used
in a number of biomedical applications such
as orthopedics, dentistry, tissue engineering,
and drug, gene and protein delivery.

A novel and stable nanosized magnesium-sub-
stituted beta-tricalcium phosphate (Mg:ο-TCP)
was synthesized by an aqueous precipitation
method, at room temperature, in one single
step, for the first time, resulting in a crystal-
line and spherical nanoparticles (diameter of Figura 46: Eu and Mg doped β-TCP nanopowders after thermal treat-
approximately 20nm), with mesoporous struc- ment at (A) 1000°C for 30 seconds and (B) 950ºC for 3 minutes. And
(C) shows the emission spectrum of Eu/Mg:β-TCP before (as-synthe-
tures and a high specific surface area (about sized) and after thermal treatments, under excitation at 394nm.

Instituto de Pesquisas Energéticas e Nucleares