ABSTRACT In this work, solid acid membrane consisting of poly(vinyl alcohol) (PVA), ammonium brom... more ABSTRACT In this work, solid acid membrane consisting of poly(vinyl alcohol) (PVA), ammonium bromide (NH4Br) and sulfuric acid (SA) has been prepared by a solution casting technique method. X-ray diffraction of the (PVA)0.75(NH4Br)0.25(H2SO4)xM polymer matrix and pure (PVA)0.75(NH4Br)0.25 revealed the difference in crystallinity between them. The effect of different amounts of SA on the conductivity of the polymer electrolytes was studied. The ionic conductivity of the prepared electrolytes can reach 3.1 × 10−2 S cm−1 at room temperature. The conductivity measurements carried out at different temperatures indicate that all the films follow Arrhenius behavior and that the activation energy decreases with the increase in SA concentration. The a.c. conductivity seems to follow the universal power law.
ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PV... more ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PVA) with magnesium bromide (MgBr2) as electrolytic salt, tetraethylene glycol dimethyl ether (TEGDME) as plasticizer and Li2O at different concentration (0.02, 0.04, 0.06 wt.%) as the filler has been prepared by solution casting technique. The polymeric film was flexible and self-standing with proper mechanical strength and studied for application in a solid-state rechargeable magnesium battery. The interactions between the filler and PVA chains are studied by X-ray and thermogravometric analyses. The conductivity increased with addition of filler reached to ∼10–5 S·cm–1 at 0.04 wt.% Li2O. The frequency dependence of ac conductivity obeys Jonscher power law. The estimated value of Mg+2 ion transference number is found to be 0.7 for high conducting film. A solid state battery based on the optimum polymer electrolyte with a configuration Mg|PE V2O5 has exhibited an open circuit voltage of 1.5 V. Also this battery has exhibited a discharge capacity ≈6.11 mA h. The discharge characteristics are found to be satisfactory as a laboratory cell.
Single crystals of KHCO3 were grown by the slow evaporation technique of an aqueous solution. Cha... more Single crystals of KHCO3 were grown by the slow evaporation technique of an aqueous solution. Characterization of the sample was done using different techniques such as X-ray diffraction, infrared spectra (IR) and the differential scanning calorimeter (DSC) technique. The analysis of the X-ray diffraction pattern indicated that the sample was a single crystal. The results obtained by IR and DSC
ABSTRACT Nanopolymer composite of PVA/CuI has been prepared as in both colloidal forms and solid ... more ABSTRACT Nanopolymer composite of PVA/CuI has been prepared as in both colloidal forms and solid layers and characterized their structure by X-ray diffraction, scanning electron microscopy, AC spectroscopy and optical absorption in UV–visible. It is observed that with the growth of CuI nanoparticles (in the range of 26–46 nm in size) reduces the PVA polymer crystallinity. The temperature dependence of bulk conductivity for PVA/CuI nanocomposite illustrated that the composites behave as the semiconducting materials with the activation energy in the range of 0.27–1.02 eV. It was observed that the direct optical band gap reduces from 3.53 eV to 1.7 eV as the concentration of CuI nanoparticles in the PVA increased from 0% to 10%. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the PVA/CuI nanocomposites were estimated from the cyclic voltammetry. The electrochemical band gap, that is, the difference between HOMO and LUMO levels also decreases with the increase in the concentration of the CuI in PVA, which is in agreement with the trend observed in the optical band gap. The current–voltage characteristics of the devices based on PVA/CuI nanocomposites, in dark shows that these composites behave as p-type semiconductors. We have also investigated the J–V characteristics under illumination and found that the power conversion efficiency is very low but these composites can be used as electron donor for bulk heterojunction solar cells along with fullerene derivatives as electron acceptor.
ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PV... more ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PVA) with magnesium bromide (MgBr2) as electrolytic salt, tetraethylene glycol dimethyl ether (TEGDME) as plasticizer and Li2O at different concentration (0.02, 0.04, 0.06 wt.%) as the filler has been prepared by solution casting technique. The polymeric film was flexible and self-standing with proper mechanical strength and studied for application in a solid-state rechargeable magnesium battery. The interactions between the filler and PVA chains are studied by X-ray and thermogravometric analyses. The conductivity increased with addition of filler reached to ∼10–5 S·cm–1 at 0.04 wt.% Li2O. The frequency dependence of ac conductivity obeys Jonscher power law. The estimated value of Mg+2 ion transference number is found to be 0.7 for high conducting film. A solid state battery based on the optimum polymer electrolyte with a configuration Mg|PE V2O5 has exhibited an open circuit voltage of 1.5 V. Also this battery has exhibited a discharge capacity ≈6.11 mA h. The discharge characteristics are found to be satisfactory as a laboratory cell.
The total conductivity of the KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in... more The total conductivity of the KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in the temperature range 300-370 K. The frequency dependence of the electrical conductivity is divided into three regions; the first one in the low-frequency range (dc conductivity), and the others in the moderate and relatively higher frequency ranges. In general, the conductivity-frequency relation
The total conductivity of KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in the... more The total conductivity of KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in the temperature range 300-370 K. The conductivity frequency dependence relation is divided into three regions: one at low frequency (dc conductivity), while the others appear at a moderate and relatively higher frequency range. In general, the conductivity frequency dependence conductivity obeys a double
ABSTRACT In this work, solid acid membrane consisting of poly(vinyl alcohol) (PVA), ammonium brom... more ABSTRACT In this work, solid acid membrane consisting of poly(vinyl alcohol) (PVA), ammonium bromide (NH4Br) and sulfuric acid (SA) has been prepared by a solution casting technique method. X-ray diffraction of the (PVA)0.75(NH4Br)0.25(H2SO4)xM polymer matrix and pure (PVA)0.75(NH4Br)0.25 revealed the difference in crystallinity between them. The effect of different amounts of SA on the conductivity of the polymer electrolytes was studied. The ionic conductivity of the prepared electrolytes can reach 3.1 × 10−2 S cm−1 at room temperature. The conductivity measurements carried out at different temperatures indicate that all the films follow Arrhenius behavior and that the activation energy decreases with the increase in SA concentration. The a.c. conductivity seems to follow the universal power law.
ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PV... more ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PVA) with magnesium bromide (MgBr2) as electrolytic salt, tetraethylene glycol dimethyl ether (TEGDME) as plasticizer and Li2O at different concentration (0.02, 0.04, 0.06 wt.%) as the filler has been prepared by solution casting technique. The polymeric film was flexible and self-standing with proper mechanical strength and studied for application in a solid-state rechargeable magnesium battery. The interactions between the filler and PVA chains are studied by X-ray and thermogravometric analyses. The conductivity increased with addition of filler reached to ∼10–5 S·cm–1 at 0.04 wt.% Li2O. The frequency dependence of ac conductivity obeys Jonscher power law. The estimated value of Mg+2 ion transference number is found to be 0.7 for high conducting film. A solid state battery based on the optimum polymer electrolyte with a configuration Mg|PE V2O5 has exhibited an open circuit voltage of 1.5 V. Also this battery has exhibited a discharge capacity ≈6.11 mA h. The discharge characteristics are found to be satisfactory as a laboratory cell.
Single crystals of KHCO3 were grown by the slow evaporation technique of an aqueous solution. Cha... more Single crystals of KHCO3 were grown by the slow evaporation technique of an aqueous solution. Characterization of the sample was done using different techniques such as X-ray diffraction, infrared spectra (IR) and the differential scanning calorimeter (DSC) technique. The analysis of the X-ray diffraction pattern indicated that the sample was a single crystal. The results obtained by IR and DSC
ABSTRACT Nanopolymer composite of PVA/CuI has been prepared as in both colloidal forms and solid ... more ABSTRACT Nanopolymer composite of PVA/CuI has been prepared as in both colloidal forms and solid layers and characterized their structure by X-ray diffraction, scanning electron microscopy, AC spectroscopy and optical absorption in UV–visible. It is observed that with the growth of CuI nanoparticles (in the range of 26–46 nm in size) reduces the PVA polymer crystallinity. The temperature dependence of bulk conductivity for PVA/CuI nanocomposite illustrated that the composites behave as the semiconducting materials with the activation energy in the range of 0.27–1.02 eV. It was observed that the direct optical band gap reduces from 3.53 eV to 1.7 eV as the concentration of CuI nanoparticles in the PVA increased from 0% to 10%. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the PVA/CuI nanocomposites were estimated from the cyclic voltammetry. The electrochemical band gap, that is, the difference between HOMO and LUMO levels also decreases with the increase in the concentration of the CuI in PVA, which is in agreement with the trend observed in the optical band gap. The current–voltage characteristics of the devices based on PVA/CuI nanocomposites, in dark shows that these composites behave as p-type semiconductors. We have also investigated the J–V characteristics under illumination and found that the power conversion efficiency is very low but these composites can be used as electron donor for bulk heterojunction solar cells along with fullerene derivatives as electron acceptor.
ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PV... more ABSTRACT In the present work, polymer electrolyte (PE) film consisting of poly(vinyl alcohol) (PVA) with magnesium bromide (MgBr2) as electrolytic salt, tetraethylene glycol dimethyl ether (TEGDME) as plasticizer and Li2O at different concentration (0.02, 0.04, 0.06 wt.%) as the filler has been prepared by solution casting technique. The polymeric film was flexible and self-standing with proper mechanical strength and studied for application in a solid-state rechargeable magnesium battery. The interactions between the filler and PVA chains are studied by X-ray and thermogravometric analyses. The conductivity increased with addition of filler reached to ∼10–5 S·cm–1 at 0.04 wt.% Li2O. The frequency dependence of ac conductivity obeys Jonscher power law. The estimated value of Mg+2 ion transference number is found to be 0.7 for high conducting film. A solid state battery based on the optimum polymer electrolyte with a configuration Mg|PE V2O5 has exhibited an open circuit voltage of 1.5 V. Also this battery has exhibited a discharge capacity ≈6.11 mA h. The discharge characteristics are found to be satisfactory as a laboratory cell.
The total conductivity of the KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in... more The total conductivity of the KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in the temperature range 300-370 K. The frequency dependence of the electrical conductivity is divided into three regions; the first one in the low-frequency range (dc conductivity), and the others in the moderate and relatively higher frequency ranges. In general, the conductivity-frequency relation
The total conductivity of KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in the... more The total conductivity of KHCO3 compound is studied in the frequency range 50 Hz-1 MHz and in the temperature range 300-370 K. The conductivity frequency dependence relation is divided into three regions: one at low frequency (dc conductivity), while the others appear at a moderate and relatively higher frequency range. In general, the conductivity frequency dependence conductivity obeys a double
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