Photonic crystals in biology

Poster Session, Tuesday, June 15
Theme A1 - B702
Preparat ion of mag netic nanoparticles with controlled morphology
Aysel Bayrak 1 ,Sema Vural 1 , Turgay Seçkin 1 *
1 Department of Chemistry, University of Inonu, Malatya, TR Türkiye 44280
Abstract-Cobalt, Nickel and zinc ferrites nanoparticles have been synthesized using the hydrothermally technique. Effects of synthesis
conditions on the crystal structure, crystallite size, lattice parameter, microstructure and magnetic properties of the produced spinel ferrites were
investigated by X-ray diffraction analysis (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM).
Since the beginning of this century, 2000, science and
engineering has seen a rapid increase in interest for materials
at the nano-scale. Nano-materials have attracted such a strong
interest because of the physical, electronic, and magnetic
properties resulting from their quantum size [1]. The potential
for nano-technology is immensely diverse with potential
applications in the fields of electronics, biomedical devices,
energy applications, military uses, and waste management [2].
Nano-materials could be utilized to design nano-transistors, to
develop and deliver medicines for locally treating diseases and
ailments within the body, and for the creation new age
weapons and armor for military applications [3]. Within the
field of nano-materials under worldwide research is the subset
of magnetic nanomaterials and magnetic nanoparticles.
Magnetic nanoparticles are of great interest for researchers
from a wide range of disciplines, including magnetic fluids,
catalysis, biotechnology/biomedicine, magnetic resonance
imaging, data storage, and environmental remediation. In
recent years, simple and reproducible methods to synthesis
magnetic nanocrystals with desired size, shape and selfassembly
have drawn much attention due to its unique size
dependant properties such as magnetic, optical, electronic and
surface reactivity [2-3]. Insights into of these unique
properties are not only important for fundamental
understanding but also have technological importance. Among
the nanocrystals, magnetic nanoparticles and its dispersions
have been used in various fields such as biomedical [4],
optical, electronics, chemical and mechanical. In addition,
these nanoparticles serve as ideal systems for fundamental
studies such as superparamagnetism, magnetic dipolar
interactions and to understand molecular interactions at
emulsion droplet interface and.
There are many techniques for the synthesis of magnetic
nano-particles including: micro-emulsion, hydrothermally
synthesis, reduction of metal-salts, gas-phase reduction of
meta l comp le xes, thermolysis of metal-poly mer co mple xes,
and thermal decomposition of metal-carbonyl complexes. In
this paper, the hydrothermally synthesis will be discussed
because it is a technique which has successfully been utilized
to synthesize magnetic nano-particles.
In this study, we investigated the formation of magnetic
oxide nanoparticles in a continuous hydrothermal reactor that
allows us to essentially separate the effects of nucleation,
growth, and agglomeration. Factors that affect the size, sizedistribution,
and morphology of nanoparticles can then be
isolated. We are particularly interested in using near-crit ical
and supercritical water in the continuous hydrothermal
environment because of the tunability of their properties by
small changes in temperature and pressure. We have produced
nanoparticles of, cobalt iron oxide (CoFe 2 O 4 ) nickel iron
oxide (NiFe 2 O 4 ) and zinc iron oxide (ZnFe 2 O 4 )
In a typical procedure for the preparation of CoFe 2 O 4 , 1 g of
cationic surfactant cetyltrimethylammonium bromide (CTAB)
was dissolved in 35 ml deionized water to form a transparent
solution. Then ferric chloride hexahydrate (FeCl 3 .6H 2 O) of 1
g was added to the solution. After 10 min stirring,
stoichiometric amount of CoCl 2 was introduced into the mixed
solution under vigorous stirring. Deionized water was added to
make the solution for a total volume of 40 ml, and pH of the
solution was adjusted to 11.0. Before being transferred to a
Teflon-lined auto-clave of 50.0 ml capacity, the solution
mixture was pretreated under an ultrasonic water bath for 30–
40 min. hydrothermal synthesis was carried out at 130 C for
15 h in an electric oven without shaking or stirring.
Afterwards, the autoclave was allowed to cool to room
temperature gradually. The black precipitate collected was
washed with distilled water three times in an ultrasonic bath to
remove any possible impurit ies. The solid was then heated at
80 C and dried under vacuum for 2 h. Other nanoparticles
synthesized with the same method.
Figure 1. M–H hysteresis loops of CoFe 2 O 4 ,NiFe 2 O 4 and ZnFe 2 O 4
nanop articles
Nickel zinc ferrites Ni x Zn 1x Fe 2 O 4 , nanoparticles have been
successfully synthesized using the hydrothermally synthesis
technique. The micrographs of nanoparticles show that they
have agglomerated morphologies consist of nanosized
spherical particles.
*Corresponding author: tseckin@inonu.edu.tr
[1] U. Ghazanfar, PhD Thesis, Punjab University, Pakistan, 2005.
[2] A.C.F.M. Costa, A.P. Diniz, V.J. Silva, R.H.G.A. Kiminami,
D.R. Cornejo,A.M. Gama, M.C. Rezende, L. Gama, J. Alloys
Compd. (2008),
[3] U.R. Lima, M .C. Nasar, R.S. Nasar, M.C. Rezende, J.H. Araújo,
J. Magn. Magn. Mater. 320 (2008) 1666.
[4] D.-L. Zhao, Q. Lv, Z.-M. Shen, J. Alloys Compd. 480 (2009)
634.
6th Nanoscience and Nanotechnology Conference, zmir, 2010 220