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conferenceseries
.com
Volume 5, Issue 6 (Suppl)
J Mat. Sci.
ISSN: 2321-6212
Advanced Materials 2017
October 26-28, 2017
OCTOBER 26-28, 2017 OSAKA, JAPAN
13
TH
INTERNATIONAL CONFERENCE ON
Advanced Materials and Nanotechnology
Pyroelectricity of electrospun polyvinylidene fluoride/tungsten oxide nanofibrous membranes
Min-Hui Chou, Chang-Mou Wu, Tolesa Fita Chala and Wen-Yuan Zeng
National Taiwan University of Science and Technology, China
T
he electronics market had a strong driving force and tendency for developing portable and wearable electronic devices
has stimulated the research interests in flexible, renewable and sustainable energy sources. Poly(vinylidene difluoride)
(PVDF) is a pyroelectric and piezoelectric polymer and widely investigated for flexible electronics because of its high flexibility,
biocompatibility and simplicity of production. A pyroelectric material such as PVDF can effectively convert thermal energy
into a temporary voltage when they are heated or cooled. If the temperature stays constant at its new value, the pyroelectric
voltage gradually disappears due to leakage current. Thus, a new heating technique such as light irradiation is important to
replace the traditional conductive heating method and leads to the poor thermal conductive PVDF polymer with repeatedly
fast heating and cooling behavior. A highly effective photo-thermal conversion material reduced tungsten oxide (WO
2.72
),
having the temperature change of 60 °C within 30 seconds under infrared light radiation (IR) was developed in our research
group. Therefore, it is highly interesting to study the pyroelectric response of the electrospun PVDF nanofibrous membranes
incorporated with efficient photo-thermal conversion material (WO
2.72
) under IR radiation. In this study, a novel flexible
pyroelectric power generator was developed by electrospun PVDF nanofibrous membranes incorporated with various
weight fractions of WO
2.72
powders. The effects of WO
2.72
and electro-spinning (ES) parameters on the crystal structure and
pyroelectric properties of PVDF/WO
2.72
nanofibrous membranes were examined. Results show that ES effectively induced
the β-phase of PVDF and the fraction of β-phase was further increased from 79% to 84% after adding with 7 wt% WO
2.72
.
Besides, the temperature of electrospun PVDF/WO
2.72
nanofibrous membrane increased rapidly and reached 98.7 °C from
room temperature while pure PVDF nanofibrous membranes only reach to 60.5 °C after 300 seconds under IR radiation. It
demonstrated that WO
2.72
presents excellent photo-thermal conversion characteristics due to the presence of free electrons or
oxygen-deficiency-induced small polarons. As for the pyroelectricity measurement, the PVDF/WO
2.72
nanofibrous membranes
were sandwiched between two electrodes and the output voltage was measured by repeated heating and cooling process.
Controlling by IR radiation, the temperature of the as received PVDF pyroelectric unit with WO
2.72
was increased from
room temperature to 51.6 °C during heating process and then rapidly cooled down to 29.9 °C within 3 minutes. When the
temperature change is 21.7 °C, the maximum output voltage of the pyroelectric unit with WO
2.72
reached to 80 mV which is
largely enhancement compare to 30 mV of the unit without WO
2.72
with 10.1 °C temperature change. Hence, the PVDF/WO
2.72
with higher temperature change induces stronger pyroelectric response than pure PVDF sample. In addition, the PVDF/
WO
2.72
also shows good stability and durability of pyroelectric power output.
Biography
Min-Hui Chou is currently pursuing her Doctorate degree in the Department of Materials Science and Engineering from National Taiwan University of Science and
Technology. Her current research interests are in the piezoelectric materials, electrospinning technology and its applications. She has published 2 papers in reputed
journals and applied 2 invention patents.
bear200718@gmail.comMin-Hui Chou et al., J Mat. Sci. 2017, 5:6
DOI: 10.4172/2321-6212-C1-008