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 CO₂ gas sensing response of SnO₂/Al₂O₃ 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-Bi₂O₃-MOX (MOX=ZrO₂, Ag₂O and TiO₂) 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 CdCl₂/H₂C₂O₄ 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