XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
166
T1: P–33
Functional properties of poly(tetrafluoroethylene) (PTFE) gasket
working in nuclear reactor condition
Magdalena Leśniak
1
, Edyta Wyszkowska
2
, Lukasz Kurpaska
2
,
Rafal Prokopowicz
3
, and Maciej Sitarz
1
1
Faculty of Materials Science and Ceramics, AGH University of Science and Technology, av. A.
Mickiewicza 30, 30-059 Krakow, Poland
2
Material Physics Department, National Centre for Nuclear Research, st. Andrzeja Soltana 7, 05-400
Otwock-Swierk, Poland, e-mail: lukasz.kurpaska@ncbj.gov.pl
3
Nuclear Facilities Operations Department, National Centre for Nuclear Research, st. Andrzeja
Soltana 7, 05-400 Otwock-Swierk, Poland
Polymers are widely used in many technological applications due to their favorable
properties. However, available data describing their structural and mechanical properties after
completing work in particular device are very scares. Polytetrafluoroethylene PTFE is a
fluorocarbon solid, as it is a high-molecular-weight compound consisting of carbon and fluorine.
PTFE is hydrophobic which means that neither water nor water-containing substances can wet
this material. In addition PTFE has one of the lowest coefficients of friction of any solid. Due to
high strength of carbon–fluorine bonds it is considered as non-reactive material. For this reason
it is often used in containers and pipework for reactive and corrosive chemicals. Because of its
chemical inertness, PTFE cannot be cross-linked like an elastomer. Therefore, it has no
"material memory" and it is not resistant to creep. Because of its superior chemical and thermal
properties, PTFE is often used as a gasket material. However, because of the propensity to
creep, the long-term performance of such seals may be worse than for elastomers.
In this study, structural and mechanical properties of PTFE specimens machined from used
and new (virgin) material working as a gasket in a valve installed in nuclear facility (MARIA
research reactor) were measured. Structural properties were investigated by means of Raman
spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques.
Mechanical properties were measured by using standard tensile experiment and nanoindentation
method. It was found out that both, mechanical and structural properties of the specimens
manufactured from used PTFE significantly differs from its original properties. Reported effect
is related to drastic rearrangement of the structure and probably creation of new morphological
structures.
Keywords: polytetrafluoroethylene; X-ray; Raman spectroscopy; nanoindenation
Acknowledgment
Financial support from Ministry of Science and Higher Education through “Young Scientist” programme is
gratefully acknowledged.
References
[1] Sergei A. Khatipov, Sergei A. Serov, Nataliya V. Sadovskaya, Elena M. Konova, Radiat. Phys. Chem.
81 (2012) 256
[2] P. J. Rae, E. N. Brown, Plymer 46 (2005) 8128
[3] A. Kitamura, T. Kobayashi, T. Meguro, A. Suzuki, T. Terai, Nucl. Instrum. Meth. B 267 (2009) 1638.
XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
167
T1: P–34
Structural properties of TiO
2
nanomaterials
Anna Kusior
1
, Joanna Banaś
1
, Anita Trenczek-Zając
1
, and Marta Radecka
1
1
AGH University of Science and Technology, Faculty of Materials Science and Ceramics,
al. A. Mickiewicza 30, 30-059 Krakow, Poland, jbanas@agh.edu.pl
Solid surfaces are characterized by active, energy-rich sites that are able to interact with
solutes in the electrolyte due to their specific electronic and spatial properties. Since adsorption
is a surface process, surface development is a key parameter of applied materials. However, an
increase in a specific surface area affects the surface energy, which affects adsorptive capacity.
Titanium dioxide nanomaterials with controllable shapes have been intensively studied over the
past decades. Anisotropic shapes lead to unique and tunable properties for widespread
applications such as photocatalysis.
New approaches to particle synthesis have made possible an unusually diverse spectrum of
particle anisotropy, including uncommon shapes and/or surface chemistry. It has been proved
that there is an optimal percentage of exposed facets in anatase TiO
2
for reaching the highest
photocatalytic activity1.
Fig. 1. XRD and Raman spectra of TiO
2
nanomaterials with different shapes.
In this paper, various titanium dioxide nanomaterials were obtained using the hydrothermal
method and flame spray synthesis. Morphology of the samples was analyzed by means of SEM
and TEM techniques. The role of particle surface area, surface charge, and hydrodynamic
diameter is reported. Comparison between XRD and Raman spectroscopy allowed to define
optimum synthesis parameters to obtain high-activity TiO
2
facets.
Keywords: TiO2; nanomaterials; structure
Acknowledgment
This project was financed by the National Science Centre (NCN) based on the decision number
2016/21/B/ST8/00457
References
[1] Q. Xiang, K. Lv, J. Yu, J. Appl. Catal. B 96 (2010) 557.
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