19 research outputs found
Synthesis and Complex Optical Characterization of Polythiophene/Poly (vinyl acetate) Composite Thin Films for Optoelectronic Device Applications
430-436In the present communication, Polythiophene/poly(vinyl acetate) (PTh/PVAc) composite thin films were synthesized by chemical oxidative polymerization method in methanol is reported. The prepared composite were characterized through X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), ultraviolet-visible (UV-Vis)spectroscopy and photoluminescence (PL) measurement. The broad peak was displayed in the PL spectra for the preparedcomposite at around 390 nm, proposed prodigious charge generation efficiency. The analysis of the optical parameters of theprepared composite was carried out by spectral analysis using a UV-Vis spectrophotometer. The obtained results, whichwere as follows: energy band gap of 4.58–5.31 eV, complex refractive index coefficient values of 1.175–1.193 and opticalconductivity values in the range of 2.58×108–5.24×108 S.cm-1 at 270 nm. The above results shows the studied compositefilms are expected to offer potential applications in optoelectronic devices
Synthesis, characterization and CO<sub>2</sub> gas sensing response of SnO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> double layer sensor
816-819Tin dioxide (SnO2)
material changes its properties depending on the ambient gas which can be
utilized as gas sensing materials. Usually changes in electrical resistance/conductance
in response to environmental gases are monitored. SnO2 and double
layer (SnO2/Al2O3) sensors have been prepared
by screen-printing technique on glass substrate. The sensors were used for
different concentration (ppm) of CO2 gas investigation at different
temperature. The sensing response (sensitivity) of SnO2/Al2O3
double layer sensor was found to be higher, compared with pure SnO2
sensor. The average grain size of SnO2 was determined from XRD
pattern and found to be 120.7 nm. The activation energy (Ea) of first order reaction (n =1) for SnO2 has been found to be 72.06 kJ/g-mol from
endo DDTA and 325.95 kJ/g-mol from exo DDTA. The microstructure of SnO2
has been studied from SEM analysis. The oxygen ions adsorb onto the surface of
material removes electrons from the bulk and create a potential barrier that
limits electron movement and resistivity. When exposed to an oxidizing gas such
as CO2 then it is chemisorbed on bridging oxygen atoms with the
formation of a surface carbonate, subsequently increasing the barrier height
and resistivity
Synthesis and Complex Optical Characterization of Polythiophene/Poly (vinyl acetate) Composite Thin Films for Optoelectronic Device Applications
In the present communication, Polythiophene/poly(vinyl acetate) (PTh/PVAc) composite thin films were synthesized by chemical oxidative polymerization method in methanol is reported. The prepared composite were characterized through X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), ultraviolet-visible (UV-Vis)spectroscopy and photoluminescence (PL) measurement. The broad peak was displayed in the PL spectra for the preparedcomposite at around 390 nm, proposed prodigious charge generation efficiency. The analysis of the optical parameters of theprepared composite was carried out by spectral analysis using a UV-Vis spectrophotometer. The obtained results, whichwere as follows: energy band gap of 4.58–5.31 eV, complex refractive index coefficient values of 1.175–1.193 and opticalconductivity values in the range of 2.58×108–5.24×108 S.cm-1 at 270 nm. The above results shows the studied compositefilms are expected to offer potential applications in optoelectronic devices
LPG sensing application of <em>ex situ</em> PPy-Bi<sub>2</sub>O<sub>3</sub>-MOX (MOX=ZrO<sub>2</sub>, Ag<sub>2</sub>O and TiO<sub>2</sub>) nanocomposites
423-427PPy-Bi2O3-MOX (MOX=ZrO2, Ag2O and TiO2) nanocomposites have been synthesized by ex situ approach. PPy-Bi2O3-MOX (MOX=ZrO2, Ag2O and TiO2) nanocomposites sensors have been fabricated for LPG sensing application. The nanocomposites have been characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), ultra violet visible spectroscopy (UV-Vis) and thermo gravimetric-differential thermal analyzer (TG-DTA) techniques. SEM micrograph exhibits irregular morphology, appropriate for gas sensing application. XRD reveals that all nanocomposites have amorphous nature. Among all the nanocomposites PBZr (PPy-Bi2O3-ZrO2) nanocomposite sensor has found good LPG sensing performance. PBZr nanocomposite sensor also exhibits better selectivity and stability against LPG. This sensor has low operating temperature against LPG of the order of 323 K and fast response and recovery time
Molecular interactions in CdCl<sub>2</sub>/H<sub>2</sub>C<sub>2</sub>O<sub>4</sub> nanofluid using acoustical studies at room temperature
670-674Nanofluids have been
prepared by dispersing nanometer size particles in base fluid. The very essence
of nanofluids research and development has to enhance the fluid macroscopic and
mega scale properties such as thermal conductivity through manipulating microscopic
physics. The acoustical properties of rhombohedral symmetry CdCl2/H2C2O4
nanofluids have been studied using ultrasonic technique at room temperature
(303 K). The ultrasonic velocity, density and viscosity of nanofluids have been
measured to manipulate the acoustical parameters such as specific acoustic
impedance, adiabatic compressibility, internal pressure, viscous relaxation
time, relative association, Gibbs free energy, intermolecular free length to
know the molecular interaction. The particle size of CdCl2/H2C2O4
fluid was estimated by using UV-Vis analysis. The results were discussed and
compared with experimental and theoretical facts