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Journal of Materials Science and Nanotechnology | Volume: 2
August 20-21, 2018 | Paris, France
Materials Science and Materials Chemistry
International Conference on
Novel composites based on nanoceramics and silver nanoparticles with antimicrobial activity for
biomedical applications
Reka Balint, Gheorghe Tomoaia, Sorin Rapuntean, Aurora Mocanu, Ossi Horovitz
and
Maria Tomoaia-Cotisel
Babes-Bolyai University of Cluj-Napoca, Romania
R
ecently, the increasing resistance of microorganisms to
antibiotics has triggered intense research for finding
alternatives. Moreover, the apparition of microbial strains
with multiple resistance has determined numerous studies
on the efficiency of metal ions, especially Ag+and silver
nanoparticles, AgNPs, on various microorganisms, mainly
bacteria and fungi. In this work, we describe first the
synthesis of spherical AgNPs in aqueous media via reduction
of silver nitrate using glucose in alkaline media in the absence
and the presence of TEOS. Also, an aqueous dispersion of
AgNPs was prepared by using a solution of silver nitrate and
a mixture of two chemical agents: sodium citrate and tannic
acid in alkaline media. The size, shape and size distribution
of AgNPs were determined by UV–Vis spectroscopy, dynamic
light scattering (DLS), atomic force microscopy (AFM) and
scanning transmission electron microscopy (STEM). The
compounds present on the surface of the AgNPs were
identified using FT-IR spectroscopy. Obtained data indicated
that the use of TEOS and the combined use of sodium citrate
and tannic acid produced spherical AgNPs dispersions, as
they allow the control of nucleation, growth and stabilization
of the synthesis process. Therefore, synthesis of new
nanostructured composite materials made from the mixture
of HAP ceramics and AgNPs at different ratios (from 0.1
to 5 wt% Ag) is realized. The HAP ceramics was previously
obtained by a wet precipitation method, while AgNPs
were prepared by reduction of silver nitrate as described
above in alkaline media. HAP and HAP & AgNPs composites
were characterized by X-ray diffraction, different imagistic
methods (TEM, SEM and STEM, AFM), UV-Vis spectroscopy
and zeta potential measurements. The antimicrobial effect
of the AgNPs alone in aqueous dispersions and in their
composites with HAP ceramics was tested on five pathogenic
species: Escherichia coli, Staphylococcus aureus, Salmonella
typhimurium, Bacillus cereus and Micrococcus luteus and
important results were obtained for biomedicalapplications.
Speaker Biography
Balint Reka graduated from the Faculty of Chemistry and Chemical Engineering at Babes-
BolyaiUniversityinCluj-Napoca,whereshegotchemistrydiploma.Now,sheisaPhDstudent
and assistant researcher at the Chemistry Physics Center at the Babes-Bolyai University.
e:
ba_reka@yahoo.com