Page 334 - 00. Complete Version - Progress Report IPEN 2014-2016

334 Materials and Nanotechnology | Progress Report

poration of modified Brazilian Clay in the EVA lated or exfoliated by EVOH chain molecules.
or EVOH followed by electron-beam irradiation The incorporation of GO in EVOH matrix led
effectively improved the mechanical proper- to obtain transparent EVOH/GO flexible films
ties of neat EVA and neat EVOH led to obtain- with improved oxygen barrier in high RH con-
ing films materials with superior properties ditions with a gain of about 160 wt. % in ten-
suitable for packaging development, concern- sile strength at break of neat EVOH and ca. of
ing mechanical properties. The superior me- 40 % in elongation at break.
chanical properties of EVOH/CLAY and EVA/
CLAY nanocomposites observed in this study Projects: IAEA-CRP # 17760 - Application of
can be attributed to the stiffness of Brazilian Radiation Technology in Development of Ad-
clay, reinforcing effects, to the degree of the vanced Packaging Materials for Food Products,
intercalation and good dispersion of the clay March 2014 to February 2017. CAPES - Pro-
layers in the matrix. grama Pesquisador Visitante Especial (PVE) -
Use of Ionizing Radiation in Modification and
Flexible films based on Ethylene–vinyl alcohol Compatibilization of Polymer Matrix Compos-
copolymer (EVOH) with graphene oxide addi- ite Materials, 02/2015 to 01/ 2018.
tion (0.1-0.5 wt. %) were prepared by melting
extrusion process, using a twin-screw extruder Synthesis and characterization of
Haake Rheomex P332, L/D 25 and blow extru- SnO2@ TiO2 nanoparticles doped
sion (laboratory line). The flexible films were with lanthanide for biological labeling.
characterized by mechanical tests, Oxygen
transmission rate (OTR), Water vapor trans- Fluoroimmunoassay is an ultrasensitive tech-
mission rate (WVTR), UV/VIS, XRD, SEM, SEM- nique for investigation of enzymes, antibod-
FEG, TG and DSC analysis ( Figure. 59). ies, cells, hormones and others. The demand
for highly sensitive systems brought the nano-
materials for biomedical and biotechnological
field. Semiconductor nanocrystals (quantum
dots) doped with lanthanide ions, when func-
tionalized with biomolecules, can be used as
luminescent biomarkers. Aiming this appli-
cation, we have been synthesized and char-
acterized nanoparticles of titanium and tin
mixed oxide doped with europium, terbium
and neodymium. The synthesis was done by
the co-precipitation and hydrothermal meth-
ods characterized by SEM, IR, XRD, TGA and
luminescence spectroscopy. These particles
Figure 59. EVOH/GO (0.1 wt. % GO nanosheets Flexible Films.
were functionalized by silica using two dif-
ferent methods, that are, the microwave and
The results of XRD diffraction patterns provide Stöber, facilitating the conjugation with bio-
clear evidence that for EVOH/GO films with logical entities (Figure 60).
0.1; 0.3 and 0.5 wt. % of GO nanosheets con-
tent some GO with stacked layers remained Figure 60. Excitation and Emission spectra of
but a large part of GO nanosheets are interca- SnO2/TiO2:Eu3+ nanoparticles (left up and

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