Enhancement in Electrical Properties of PEO Based Nano-Composite Gel Electrolytes

Vol. 2  Issue 3
Year: 2014
Issue:Oct-Dec
Title:Enhancement in Electrical Properties of PEO Based Nano-Composite Gel Electrolytes
Author Name:Rajiv Kumar
Synopsis:

The nano-composite polymer gel electrolytes containing polyethylene oxide (PEO), triflic acid, dimethylacetamide (DMA), propylene carbonate (PC), ethylene carbonate (EC) and nano-porous alumina filler (Al2O3) have been synthesized. The AC impedance has been studied to evaluate Ionic conductivity of the electrolytes. pH, viscosity and thermal properties of these electrolytes have also been studied. The increase in conductivity has been observed with the addition of polymer to liquid electrolytes which has been explained to be due to the breaking of ion aggregates present in electrolytes. The increase in free H+ ion concentration upon breaking of ion aggregates has also been observed in pH measurements. It was observed that the conductivity increases with an increase in the concentration of nano filler and two maxima in conductivity have also been observed. The maximum conductivity of 1.02 × 10-2 S/cm has been observed at 8 wt% concentration of nano filler. A possible mechanism for the increase in conductivity could be the creation of additional hopping sites and favorable conducting pathways for migrating ionic species though Lewis acid- base type interactions between ionic species and O- sites on the filler grain surface. Temperature dependence conductivity of polymer gel electrolytes follows Arrhenius behaviour. The gels containing DMA are stable over upto 125o C range of temperature, while gels based on PC and EC are stable only upto 40oC temperature range which looses their gelling nature above 40o C. The conductivity does not show any appreciable change with temperature which is desirable for their use in smart electrochemical applications at low temperature.

Finite Element Analysis For Optimal Design Of Filament Wound Composite Tubes

Vol. 2  Issue 3
Year: 2014
Issue:Oct-Dec
Title:Finite Element Analysis For Optimal Design Of Filament Wound Composite Tubes
Author Name:Yasser Rihan and B. Abd El-Bary 
Synopsis:

Filament wound composite tubes can be used for making high-pressure storage tanks, rocket motor cases, and launch tubes, and for commercial applications, such as golf club shafts and fishing rods. A variety of fibers and resins can be used, depending on the cost and the level of performance needed. This paper presents the results of a mathematical modeling investigation into the behavior of the filament wound composite tubes subjected to various loading conditions. Filament wound tubes were modeled as multi layered orthotropic tubes and several analyses were performed on these tubes by using finite element method (FEM). Three types of fiber epoxy tubes with different wind angles, level of orthotropy and various ratios of the loading conditions were produced and tested for the behavior of filament wound composite tubes. The required data were obtained for the design of filament wound composite tubes under combined loading. The mathematical model used was validated using experimental data obtained from filament wound tube tests in previous studies.

Comparison Of Composite Proton Conducting Polymer Gel Electrolytes Containing Weak Aromatic Acids

Vol. 2  Issue 2
Year: 2014
Issue:Jul-Sep
Title:Comparison Of Composite Proton Conducting Polymer Gel Electrolytes Containing Weak Aromatic Acids
Author Name:Rajiv Kumar
Synopsis:

Composite proton conducting non aqueous polymer gel electrolytes have been synthesized by dispersing nano sized fumed silica to the polymer gel electrolytes containing polymethylmethacrylate (PMMA), dimethylacetamide (DMA), benzoic acid (BA) and ortho-hydroxy benzoic acid (o-OHBA). These electrolytes have been characterized by complex impedance spectroscopy, viscosity and pH measurements. The effect of acid, polymer and fumed silica on -4 conductivity, pH and viscosity has been studied for gel electrolytes. Maximum conductivity of 2.95 x 10 S/cm and 5 o viscosity of 1.64 x 10 mPas at 25 C has been obtained. The conductivity of composite gels does not show any appreciable change with time and only a small change in conductivity is observed over the operational range of temperature, which is desirable for their use in device applications.

Electric Properties Of Rare Earth Doped Strontium M-Type Hexagonal Ferrites

Vol. 2  Issue 2
Year: 2014
Issue:Jul-Sep
Title:Electric Properties Of Rare Earth Doped Strontium M-Type Hexagonal Ferrites
Author Name:Taminder Singh, Arun Katoch and Iqbal Singh
Synopsis:

The Seebeck Coefficient for the strontium ferrites Sr RE Fe O (where RE = Dy, x = 0.0, 0.10, 0.20 and 0.30), which have 1-x x 12 19 been prepared by employing the ceramic technique, were studied in the temperature range 313-473K. The value of thermoelectric power seems to increase with increasing temperature where as the AC conductivity has been observed to be independent of frequency at high temperatures for all values of x. In the relatively low temperature region, thermoelectric power value has been found to be negative confirming that the majority of carriers are electrons thereby indicating the rare earth substituted strontium ferrites to be classified as n-type semiconductors. The X-ray diffraction patterns show that the prepared samples have a single phase. The lattice parameters 'c' and 'a' were found to decrease whereas the X-ray density increases with increasing RE content. It has been found that the value of electrical conductivity also increases with an increase in RE content. The dispersion of dielectric constant has been discussed in the light of Koops model and hopping conduction mechanism.

Spectroscopic Investigations Of Anatase Titania Nanoparticles

Vol. 2  Issue 2
Year: 2014
Issue:Jul-Sep
Title:Spectroscopic Investigations Of Anatase Titania Nanoparticles
Author Name:Katlakanti Mohan Reddy, Devi L G and P K Sahoo
Synopsis:

To investigate the relationship between the particle size and the Raman bands of TiO nanoparticles, two different size- 2 selected samples of TiO nanoparticles were investigated using Transmission Electron Microscopy (TEM), High Resolution 2 TEM (HRTEM), X-ray Photoelectron absorption Spectroscopy (XPS), and Fourier Transform Raman spectroscopy (FTRaman). In the Raman spectra, both broadening and shifts of the Raman bands with decreasing particle diameter were observed. In this paper, these Raman shifts are attributed to the effects of decreasing particle size on the force constants and vibrational amplitudes of the nearest neighbor bonds.

Photoluminescence And Dielectric Studies Of Ion Induced Polyethylene Naphthalate

Vol. 2  Issue 2
Year: 2014
Issue:Jul-Sep
Title:Photoluminescence And Dielectric Studies Of Ion Induced Polyethylene Naphthalate
Author Name:Kusum Devgan, Navjeet Kaur, Sonika Thakur, Manpreet Kaur and Lakhwant Singh 
Synopsis:

Dielectric properties along with photoluminescence phenomenon of ion induced Polyethylene naphthalate (PEN) were 3+ 6+ 10+ analyzed. Li , C , Ni ion beams were used to analyze the modifications induced by swift heavy ions as a function of ion 11 12 2 fluence, ranging from 1x10 to 3x10 ions/cm . Blue shift is observed in PL behavior. Dielectric constant (ε′) for pristine and irradiated samples has also been calculated, which increases with the increase in ion fluence.

Spin Speed Dependence Of Optical Band Gap Of SOL Gel Spin Coated Zinc Oxide Thin Films

Vol. 2  Issue 2
Year: 2014
Issue:Jul-Sep
Title:Spin Speed Dependence Of Optical Band Gap Of SOL Gel Spin Coated Zinc Oxide Thin Films
Author Name:Rajesh Kumar, Aakanksha Sahu, Narinder Arora, Rabia Sareen and Gagandeep Kaur 
Synopsis:

The zinc oxide (ZnO) thin films have been obtained by sol gel spin coating technique on to the glass substrates kept at  4000 C. The conditions have been optimized to obtain quality films. Optical absorption studies to find optical band gap of the films have been made through UV-Visible spectroscopy in the spectral range of 200 -1100 nm. Effect of spin speed on the optical band gap of these films has been studied. Results show that optical band gap of the films get modified on increasing the spin speed of films.