Page 50 - PR 2014 2016 10 Materials and Nanotechnology

326 Materials and Nanotechnology | Progress Report

of the film and caused structural changes in the
EVOH, or EVA component, and leads to obtain a
flexible film with major melting enthalpy and,
consequently, major crystallinity percentage.
However, when EVOH and EVA flexible film
content only 1 % Clay addition (falta conec-
tor??) were irradiated at 150 and 200 kGy a
significant gain of up to 30 % in tensile strength
and elongation at break was observed when
compared with non-irradiated samples. It may
be claimed that the incorporation of modified
Brazilian Clay in the EVA or EVOH followed by
electron-beam irradiation effectively improved Figure 59. EVOH/GO (0.1 wt. % GO nanosheets Flexible Films.
the mechanical properties of neat EVA and
neat EVOH led to obtaining films materials conditions with a gain of about 160 wt. % in
with superior properties suitable for packaging tensile strength at break of neat EVOH and ca.
development, concerning mechanical prop- of 40% in elongation at break.
erties. The superior mechanical properties of
EVOH/CLAY and EVA/CLAY nanocomposites Projects: IAEA-CRP # 17760 - Application of
observed in this study can be attributed to the Radiation Technology in Development of Ad-
stiffness of Brazilian clay, reinforcing effects, vanced Packaging Materials for Food Products,
to the degree of the intercalation and good March 2014 to February 2017. CAPES - Pro-
dispersion of the clay 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- SnO @ TiO nanoparticles doped with
2
2
sion (laboratory line). The flexible films were lanthanide for biological labeling.
characterized by mechanical tests, Oxygen
transmission rate (OTR), Water vapor transmis- Fluoroimmunoassay is an ultrasensitive tech-
sion rate (WVTR), UV/VIS, XRD, SEM, SEM-FEG, nique for investigation of enzymes, antibod-
TG and DSC analysis ( Figure. 59). ies, cells, hormones and others. The demand
for highly sensitive systems brought the
The results of XRD diffraction patterns provide nanomaterials for biomedical and biotech-
clear evidence that for EVOH/GO films with nological field. Semiconductor nanocrystals
0.1; 0.3 and 0.5 wt. % of GO nanosheets content (quantum dots) doped with lanthanide ions,
some GO with stacked layers remained but a when functionalized with biomolecules, can
large part of GO nanosheets are intercalated be used as luminescent biomarkers. Aiming
or exfoliated by EVOH chain molecules. The this application, we have been synthesized
incorporation of GO in EVOH matrix led to and characterized nanoparticles of titanium
obtain transparent EVOH/GO flexible films and tin mixed oxide doped with europium,
with improved oxygen barrier in high RH terbium and neodymium. The synthesis was

Instituto de Pesquisas Energéticas e Nucleares