Dc Ionic Conductivity

Poly[aniline-coN -(2-hydroxyethyl) aniline] was synthesized in an aqueous hydrochloric acid medium with a determined feed ratio by chemical oxidative polymerization. This polymer was used as a functional conducting polymer intermediate because of its side-group reactivity. To synthesize the alkyl-substituted copolymer, the initial copolymer was reacted with NaH to obtain the N-and O-anionic copolymer after the reaction with octadecyl bromide to prepare the octadecyl-substituted polymer. The microstructure of the obtained polymers was characterized by Fourier transform infrared spectroscopy, 1 H-NMR, and X-ray diffraction. The thermal behavior of the polymers was investigated by thermogravimetric analysis and differential scanning calorimetry. The morphology of obtained copolymers was studied by scanning electron microscopy. The cyclic voltammetry investigation showed the electroactivity of poly [aniline-coN -(2-hydroxyethyl) aniline] and N and O-alkylated poly[aniline-coN -(2-hydroxyethyl) aniline]. The conductivities of the polymers were 5 Â 10 À5 S/cm for poly[aniline-coN -(2-hydroxyethyl) aniline] and 5 Â10 À7 S/ cm for the octadecyl-substituted copolymer. The conductivity measurements were performed with a four-point probe method. The solubility of the initial copolymer in common organic solvents such as N-methyl-2-pyrrolidone and dimethylformamide was greater than polyaniline. The alkylated copolymer was mainly soluble in nonpolar solvents such as n-hexane and cyclohexane. V

Ceramic samples of (Bi[Formula: see text]Pbx)NbO4([Formula: see text], 0.025, 0.05, 0.10, 0.15, 0.20) with 0.75[Formula: see text]wt.% V2O5addition sintered at 920[Formula: see text]C, 940[Formula: see text]C and 960[Formula: see text]C are investigated. Pb is selected as a substitute for Bi[Formula: see text] in BiNbO4ceramics as it exists in two stable valence states of [Formula: see text]2 and [Formula: see text]4 and the average valency matches to that of Bi[Formula: see text]. The average Shannon radius (for octahedral coordination) of Pb[Formula: see text] (1.19[Formula: see text]Å) and Pb[Formula: see text](0.775[Formula: see text]Å) cations is 0.9825[Formula: see text]Å, which is similar to that of Bi[Formula: see text] ion (1.03[Formula: see text]Å). The dense ([Formula: see text]%) polycrystalline (Bi[Formula: see text]Pbx)NbO4samples fabricated mostly reveal orthorhombic (Pnna) phase ([Formula: see text]-BiNbO4, Sp. Gp. 52) by powder XRD. Presence of satellite Pb2Nb2O7pha...

Ceramic samples of (Bi[Formula: see text]Pbx)NbO4([Formula: see text], 0.025, 0.05, 0.10, 0.15, 0.20) with 0.75[Formula: see text]wt.% V2O5addition sintered at 920[Formula: see text]C, 940[Formula: see text]C and 960[Formula: see text]C are investigated. Pb is selected as a substitute for Bi[Formula: see text] in BiNbO4ceramics as it exists in two stable valence states of [Formula: see text]2 and [Formula: see text]4 and the average valency matches to that of Bi[Formula: see text]. The average Shannon radius (for octahedral coordination) of Pb[Formula: see text] (1.19[Formula: see text]Å) and Pb[Formula: see text](0.775[Formula: see text]Å) cations is 0.9825[Formula: see text]Å, which is similar to that of Bi[Formula: see text] ion (1.03[Formula: see text]Å). The dense ([Formula: see text]%) polycrystalline (Bi[Formula: see text]Pbx)NbO4samples fabricated mostly reveal orthorhombic (Pnna) phase ([Formula: see text]-BiNbO4, Sp. Gp. 52) by powder XRD. Presence of satellite Pb2Nb2O7pha...

Ceramic samples of (Bi[Formula: see text]Pbx)NbO4([Formula: see text], 0.025, 0.05, 0.10, 0.15, 0.20) with 0.75[Formula: see text]wt.% V2O5addition sintered at 920[Formula: see text]C, 940[Formula: see text]C and 960[Formula: see text]C are investigated. Pb is selected as a substitute for Bi[Formula: see text] in BiNbO4ceramics as it exists in two stable valence states of [Formula: see text]2 and [Formula: see text]4 and the average valency matches to that of Bi[Formula: see text]. The average Shannon radius (for octahedral coordination) of Pb[Formula: see text] (1.19[Formula: see text]Å) and Pb[Formula: see text](0.775[Formula: see text]Å) cations is 0.9825[Formula: see text]Å, which is similar to that of Bi[Formula: see text] ion (1.03[Formula: see text]Å). The dense ([Formula: see text]%) polycrystalline (Bi[Formula: see text]Pbx)NbO4samples fabricated mostly reveal orthorhombic (Pnna) phase ([Formula: see text]-BiNbO4, Sp. Gp. 52) by powder XRD. Presence of satellite Pb2Nb2O7pha...

Ceramic samples of (Bi[Formula: see text]Pbx)NbO4([Formula: see text], 0.025, 0.05, 0.10, 0.15, 0.20) with 0.75[Formula: see text]wt.% V2O5addition sintered at 920[Formula: see text]C, 940[Formula: see text]C and 960[Formula: see text]C are investigated. Pb is selected as a substitute for Bi[Formula: see text] in BiNbO4ceramics as it exists in two stable valence states of [Formula: see text]2 and [Formula: see text]4 and the average valency matches to that of Bi[Formula: see text]. The average Shannon radius (for octahedral coordination) of Pb[Formula: see text] (1.19[Formula: see text]Å) and Pb[Formula: see text](0.775[Formula: see text]Å) cations is 0.9825[Formula: see text]Å, which is similar to that of Bi[Formula: see text] ion (1.03[Formula: see text]Å). The dense ([Formula: see text]%) polycrystalline (Bi[Formula: see text]Pbx)NbO4samples fabricated mostly reveal orthorhombic (Pnna) phase ([Formula: see text]-BiNbO4, Sp. Gp. 52) by powder XRD. Presence of satellite Pb2Nb2O7pha...

Ceramic samples of (Bi[Formula: see text]Pbx)NbO4([Formula: see text], 0.025, 0.05, 0.10, 0.15, 0.20) with 0.75[Formula: see text]wt.% V2O5addition sintered at 920[Formula: see text]C, 940[Formula: see text]C and 960[Formula: see text]C are investigated. Pb is selected as a substitute for Bi[Formula: see text] in BiNbO4ceramics as it exists in two stable valence states of [Formula: see text]2 and [Formula: see text]4 and the average valency matches to that of Bi[Formula: see text]. The average Shannon radius (for octahedral coordination) of Pb[Formula: see text] (1.19[Formula: see text]Å) and Pb[Formula: see text](0.775[Formula: see text]Å) cations is 0.9825[Formula: see text]Å, which is similar to that of Bi[Formula: see text] ion (1.03[Formula: see text]Å). The dense ([Formula: see text]%) polycrystalline (Bi[Formula: see text]Pbx)NbO4samples fabricated mostly reveal orthorhombic (Pnna) phase ([Formula: see text]-BiNbO4, Sp. Gp. 52) by powder XRD. Presence of satellite Pb2Nb2O7pha...

Ceramic samples of (Bi[Formula: see text]Pbx)NbO4([Formula: see text], 0.025, 0.05, 0.10, 0.15, 0.20) with 0.75[Formula: see text]wt.% V2O5addition sintered at 920[Formula: see text]C, 940[Formula: see text]C and 960[Formula: see text]C are investigated. Pb is selected as a substitute for Bi[Formula: see text] in BiNbO4ceramics as it exists in two stable valence states of [Formula: see text]2 and [Formula: see text]4 and the average valency matches to that of Bi[Formula: see text]. The average Shannon radius (for octahedral coordination) of Pb[Formula: see text] (1.19[Formula: see text]Å) and Pb[Formula: see text](0.775[Formula: see text]Å) cations is 0.9825[Formula: see text]Å, which is similar to that of Bi[Formula: see text] ion (1.03[Formula: see text]Å). The dense ([Formula: see text]%) polycrystalline (Bi[Formula: see text]Pbx)NbO4samples fabricated mostly reveal orthorhombic (Pnna) phase ([Formula: see text]-BiNbO4, Sp. Gp. 52) by powder XRD. Presence of satellite Pb2Nb2O7pha...

The tight-binding linear muffin-tin orbital (TB-LMTO) with in the local density approximation is used to calculate total energy, lattice parameters, bulk modulus, density of states and energy band structures of americium monochalcogenides at ambient as well as high pressure. It is found that AmX (X=S, Se, Te) compounds are stable in NaCl – type structure under ambient pressure. We predict a structural phase transition from NaCl-type (B1-phase) structure to CsCl-type (B2-phase) structure for these compounds in the pressure range of 26.0 – 15.0 GPa (AmS to AmTe). From energy band diagram it is observed that AmX compounds exhibit metallic behaviour. The calculated ground state properties such as lattice parameters and bulk modulus are in general good agreement with available experimental and theoretical data.

In this work, samples of pure polystyrene and polystyrene (PS) doped with (pomegranate peel) were prepared using casting method .The effect of addition of pomegranate peel (PP) concentration on optical properties of poly styrene have been studied in the wavelength range (200-800)nm. The absorption coefficient, energy gap, refractive index and extinction coefficient have been determined. The results show that the optical constants change with increase of PP concentration.

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This study covers the synthesis of polymers of aniline, m-chloroaniline and their copolymers by chemical oxidation in HCl medium. The composition of the copolymers was varied by varying the comonomer feed ratio in the polymerization reactions. For examining the effect of composition on copolymer solubility, viscosity, density, spectral characterization and electrical properties were studied. The electrical conductivity of the compressed pellets were measured by two probe method. The copolymer exhibits excellent solubility in DMF, DMSO and THF. The spectroscopic analysis, solubility test, viscosity, density and electrical conductivity suggest that aniline and m-chloroaniline units are distributed along the copolymer chain and the properties of copolymers can be modified by varying the monomer composition in copolymerization reactions. It was found that the room temperature conductivity of the copolymer decreases with increase of the m-chloroaniline content in copolymerization reaction, because of the introduction of the-Cl À group reducing the conjugation of the polymer chain.

In this work, samples of pure polystyrene and polystyrene (PS) doped with (pomegranate peel) were prepared using casting method .The effect of addition of pomegranate peel (PP) concentration on optical properties of poly styrene have been studied in the wavelength range (200-800)nm. The absorption coefficient, energy gap, refractive index and extinction coefficient have been determined. The results show that the optical constants change with increase of PP concentration.

In this paper, some theoretical attenuation  parameters was calculated for shields  made up of composite materials basis polymer (Epoxy )  with added materials (C,Ni,PbO,Bi) with different concentrations (10,20,30,40,50)wt% , where the effect of concentrations variation on the attenuation coefficients values , effective atomic number and shields density has been studying. The computer program code X-Com was used to calculate the attenuation parameter values at different energies (0.662,1.173,1.332)MeV .Results shows that there is a clear change in the values of these parameters with the change of concentration ratios.

Electropolymerization of aniline and 2,4-dinitrophenol on composite graphite electrode in phosphoric acid medium has been investigated by cyclic voltammetry. The copolymer has been synthesized in a mole ratio of 1:1 of aniline and 2,4-dinitrophenol in aqueous medium with para-toluene sulfonic acid and KCl as the binary supporting electrolytes. The properties of the modified electrodes have been characterized and compared with each other by FTIR spectroscopy. The inductive behavior of polyaniline and copolymers of aniline with 2,4-dinitrophenol has been identified via electrochemical impedance spectroscopy by determining parameters such as impedance and capacitance.

Composite materials are used in many industries such: solar cells, optoelectronic device elements, light emitting diodes, aircraft, military and car industry. In this paper, effect of potassium chloride on physical and optical properties of polystyrene has been studied to use the new material in many applications. The physical properties showed that the absorption of composite to water increases with increase time of the submerging in the water. Also, diffusion coefficient increases with increase the potassium chloride concentrations. The optical properties was measured in wavelength range from 200nm to 800nm. The experimental results showed that absorbance of polystyrene increases with increase the potassium chloride concentrations. The optical constants (absorption coefficient, energy band gap, extinction coefficient, refractive index and real and imaginary parts of dielectric constants) are increasing with increase the potassium chloride concentrations.

Electron paramagnetic resonance, optical transmission spectra and DC conductivity of the glasses 2xMX Á (0.30Àx)M 2 O Á 0.70B 2 O 3 (M=Na or K; X=Cl or Br) (0:01pxp0:10) containing 2.0 mol% of V 2 O 5 have been studied. The spin-Hamiltonian parameters (SHP) of the VO 2+ ions, the dipolar hyperfine parameter, P, the Fermi contact interaction parameter, K, and the molecular orbital coefficients (a 2 and g 2) have been calculated. It is observed that in KX Á K 2 O Á B 2 O 3 (X=Cl or Br) glasses, the tetragonal nature of V 4+ O 6 complex decreases with KBr for xX0:05: An increase in the 2KX:K 2 O ratio (xX0:05) also results in the contraction of 3dxy orbit of the unpaired electron in the vanadyl ion, whereas in case of NaX Á Na 2 O Á B 2 O 3 (X=Cl or Br) glasses, the SHP are independent of change in 2NaX:M 2 O ratio. It is observed that the SHP in these alkali halide borate glasses are independent of the theoretical optical basicity, L th : It is also observed that the DC conductivity increases with increase in temperature. The order of conductivity is 10 À6 O À1 m À1 at low temperatures and 10 À4 O À1 m À1 at high temperatures. In MCl Á M 2 O Á B 2 O 3 (M=Na or K) glasses, the conductivity increases and the activation energy decreases with an increase in mol% of the NaCl or KCl content whereas, in MBr Á M 2 O Á B 2 O 3 (M=Na or K) glasses, the conductivity first increases and then decreases with mol% of the MBr content.

The PVA/TiO 2 composite polymer membranes were prepared by a sol-Gel casting method, the weight of PVA is constant (1gm) while the TiO 2 powder weights were (0.01, 0.02, 0.03, 0.04, 0.05) gm, the density of the samples were measured by the weight method. In order to evaluate the mechanical properties of PVA/TiO 2 composite the ultrasonic measurements were performed at the composites these properties are ultrasonic velocity, compressibility, acoustic impedance and bulk modulus at different frequencies (25,30,35,40) kHz , another acoustic mechanical properties were measured and calculated at a same time such as the ultrasonic wave amplitude before and after absorption by composite were measured using oscilloscope, then we calculated absorption coefficient and transmittance, shear viscosity , relaxation time and relaxation amplitude. It was found that there is significant relationship between ultrasonic velocity and material properties also results show that adding TiO 2 effect on the ...

Glasses of the 20K2O 5CdO 60B2O3 -15SiO2 and (20-x) K2O 5CdO 60B2O3 15SiO2 – xV2O5 (where x=0.1to 0.5mol %) KCdBSi systems were prepared by melt quenching technique. Optical and structural properties of undoped glass, and glasses doped with VO 2+ ions were examined. Their structural properties were determined with XRD, Fourier Transform Infrared (FTIR) and Electron Paramagnetic Resonance spectra (ESR) and Optical absorption spectra. Optical band gaps of glass samples were determined for direct and indirect transitions from the absorption spectra. Through the fundamental Ultra Violet absorption edges of the glasses, the Optical band gap energies and Urbach energies were evaluated. The ESR spectra of all the glass samples exhibit resonance signals characteristic of VO 2+ ions. The values of Spin-Hamiltonian parameters indicated that the VO 2+ ion in KCdBSi glasses were present in octahedral sites with tetrahedral compression and belong to C4v symmetry. Spin Hamiltonian parameters ‘g’ ...

In this paper, effects of lattice strain on dielectric properties of Sr[Formula: see text]CaxBi2Nb2O9 ([Formula: see text]–0.5 in steps of 0.1) ceramics are reported. High frequency dipolar polarization is observed to increase for 10% calcium addition and suppresses thereafter on higher calcium concentrations. The dielectric loss values for all doped samples were lower compared to undoped one at frequencies beyond 1[Formula: see text]kHz. The sample with [Formula: see text] shows room temperature dielectric constant in the range (130[Formula: see text][Formula: see text][Formula: see text]12) over a wide frequency range from 50[Formula: see text]Hz to 1[Formula: see text]MHz also minimum dielectric loss among all other sample for the same frequency range. Remarkable increase in Curie temperature ([Formula: see text]) by 50[Formula: see text]C is recorded in the present work by increasing 10% calcium content in SBN compostion. All higher doped samples indicate increase in [Formula: s...

In this paper, effects of lead doping on the lattice response and phase transitions of Sr 1Kx Pb x Bi 2 Nb 2 O 9 (xZ0.0-0.5 in steps of 0.1) ferroelectric ceramics are reported. It is observed that structure attains more tetragonality with doping of lead up to 40%. Increased orthorhombic distortion is observed for undoped SBN and 50 at.% lead substituted SBN. Phase transitions for all samples were studied using Curie temperature measurements and are explained in terms of lattice response of these ceramics. Sample with xZ0.5 shows decreased tetragonal strain and Curie temperature. Relationship of polarization with lattice response is discussed.

The purpose of the study to determine the thermal properties and mechanical properties of thermoplastic composites of high density polyethylene (HDPE) with filler natural zeolite modified with cetyl trimethyl ammonium bromide (CTAB) and purification of the calcination process. Composite manufacture begins with a blens of calcined natural zeolites and zeolite synthesis CTAB. Then, the mixing of materials in an internal mixer at a temperature of 150 o C laboplastomil for 9 minutes. The results of the internal mixer and molded by hot press and cold press sheets that subsequently result in a dumbell with JIS K 6781 standard mechanical tests, ASTM D 3418-03 analysis thermal. Mechanical analysis results showed values ??of tensile strength and elongation at break of HDPE with the highest composite filler modified zeolite CTAB/PE-g-MA at 24.964 MPa and 398.89 mm. The Young 's modulus of the highest indicated HDPE composites with zeolite filler CTAB was 720.76 MPa. While the results of t...

In this study, to synthesize various glasses for the system (20-x) Li 2 CO 3-10 ZnO-5Al 2 O 3-65H 3 BO 3-xV 2 O 5 with (x = 0, 0.2, 0.4, 0.6 and 0.8 mol%) the melt-quenching technique was used. Fourier transform infrared (FT-IR), Electron paramagnetic resonance (EPR) and Ultraviolet-visible (UV-Vis) spectroscopy characterizations are analyzed for the prepared glass samples. The FTIR analyses indicated the presence of various bonds comprising V-O-V, B-O-B, and B-OH, which were attributed to different vibrations. The presence of VO 2+ species was observed in the place of isolated V 4+ ions in a ligand field of C 4v symmetry from the EPR spectra of these glass samples.From UV-Vis absorption spectra two characteristics bands related to 2 B 2 → 2 E 1 and 2 B 2 → 2 B 1 transitions of VO 2+ are observed in the prepared glass samples.

Glasses with composition CdO-(20-x) SrO-B 2 O 3-SiO 2-x V 2 O 5 (CdSBSi) (x = 0.5, 1, 1.5, 2, 2.5 mol%) were prepared by melt quenching technique. The amorphous nature of prepared glasses is confirmed by X-ray diffraction. Optical absorption spectra, electron paramagnetic resonance (EPR) and Fourier transform infrared (FTIR) measurements were also carried out for the prepared glass samples. The optical band gap energy (E opt) and Urbach energy (DE) were calculated from their ultraviolet edges. The theoretical values of optical basicity (K th) of glasses have been evaluated. The optical absorption spectrum exhibits two band characteristic of VO 2? ions in tetragonally distorted octahedral site symmetry. The two bands have been assigned to the transitions 2 B 2 ? 2 B 1 and 2 B 2 ? 2 E in the decreasing order of energy. The spin-Hamiltonian parameters (g and A), bonding parameters (b* 2 and e Ã2 p), Fermi contact interaction parameter (K) have been evaluated from the EPR spectra. The VO 2? site symmetry is ascribed to a tetragonally (C 4v) distorted octahedron. FTIR spectra of these glasses were analyzed in order to identify the contribution of each component to the local structure. The physical properties of these glasses were also evaluated.

The effects of vibration (longitudinal &transverse) on thermal imaging for truncated object target are considered, a conventional thermal camera and a Mathcad program to reconstruct the Bar Spread Function (BSF) degraded because vibration of target .A aerial photography is used as application in imaging the target ,results indicates that even low amplitude vibration greatly affects the predicted target detection.

The purpose of the study to determine the thermal properties and mechanical properties of thermoplastic composites of high density polyethylene (HDPE) with filler natural zeolite modified with cetyl trimethyl ammonium bromide (CTAB) and purification of the calcination process. Composite manufacture begins with a blens of calcined natural zeolites and zeolite synthesis CTAB. Then, the mixing of materials in an internal mixer at a temperature of 150 o C laboplastomil for 9 minutes. The results of the internal mixer and molded by hot press and cold press sheets that subsequently result in a dumbell with JIS K 6781 standard mechanical tests, ASTM D 3418-03 analysis thermal. Mechanical analysis results showed values of tensile strength and elongation at break of HDPE with the highest composite filler modified zeolite CTAB/PE-g-MA at 24.964 MPa and 398.89 mm. The Young 's modulus of the highest indicated HDPE composites with zeolite filler CTAB was 720.76 MPa. While the results of the thermal analysis shows the value of the highest melting point and decomposition on HDPE composites with zeolite calcined/PE-g-MA at 151.23 0 C and 488.23 0 C.

The purpose of this research is to create nano particles rice rusk ash used as a filler in thermoplastic high density poliethylen (HDPE) and nano-mechanical properties of the resulting composites. The method of rice husk ash made way smoothed by ball mill PM 200 for 1 hour, the filter results in a ball mill with a sieve size of 200 mesh (74 µm), rice husk ash is dissolved in 2.5M NaOH for 4 hours and then stirred with a magnetic stirrer, then at Ball mill for 15 hours at a rate of 450 rpm, nano rice husk ash is used as filler in HDPE thermoplastic composition (2,4,6,8,10) wt% were blends in an internal mixer at a temperature of 150 0 C laboplastomil at a rate of 60 rpm for 10 minutes. Nano composite mechanical properties were analyzed with Universal Testing Mechanic. The results obtained rice husk ash silica composition of 89.6 wt%, the particle size of 50.6 nm, the results of the mechanical properties of tensile strength and elongation at break of an increase in the composition of the mixture 2 to 4% by weight.

Composites consisting of poly-vinyl alcohol as matrix and lithium fluoride as a filler has been investigated with different percentages of lithium fluoride are (0,5,10, and 15) wt.%. The electrical conductivity of composite has been studied at different temperature. The results showed that the D.C electrical conductivity increases with increasing the lithium fluoride concentrations and temperature. Also the activation energy change with increasing of lithium fluoride concentration.

The purpose of the study to determine the thermal properties and mechanical properties of thermoplastic composites of high density polyethylene (HDPE) with filler natural zeolite modified with cetyl trimethyl ammonium bromide (CTAB) and purification of the calcination process. Composite manufacture begins with a blens of calcined natural zeolites and zeolite synthesis CTAB. Then, the mixing of materials in an internal mixer at a temperature of 150 o C laboplastomil for 9 minutes. The results of the internal mixer and molded by hot press and cold press sheets that subsequently result in a dumbell with JIS K 6781 standard mechanical tests, ASTM D 3418-03 analysis thermal. Mechanical analysis results showed values of tensile strength and elongation at break of HDPE with the highest composite filler modified zeolite CTAB/PE-g-MA at 24.964 MPa and 398.89 mm. The Young 's modulus of the highest indicated HDPE composites with zeolite filler CTAB was 720.76 MPa. While the results of the thermal analysis shows the value of the highest melting point and decomposition on HDPE composites with zeolite calcined/PE-g-MA at 151.23 0 C and 488.23 0 C.

The present work reports the oxidative synthesis of poly aniline using K 2 Cr 2 O 7 as an oxidizing agent and H 2 SO 4 as dopant. The synthesized polymer was characterized by solubility test and UVvisible spectroscopic technique. The synthesized polymer (poly aniline) was insoluble in ethanol, acetone, benzene and water. The absorbance of UV-visible spectra shows two reductive peaks at some wake length. The band observed at 327 -365 nm for the PANI samples corresponds to n-p * transitions of aniline and the broad band at 600 -620 nm is due to n-p * transitions of quinine-imine groups.

In this paper, effects of lead doping on the lattice response and phase transitions of Sr1KxPbxBi2Nb2O9 (x=0.0–0.5 in steps of 0.1) ferroelectric ceramics are reported. It is observed that structure attains more tetragonality with doping of lead up to 40%. Increased orthorhombic distortion is observed for undoped SBN and 50 at.% lead substituted SBN. Phase transitions for all samples were studied using Curie temperature measurements and are explained in terms of lattice response of these ceramics. Sample with x=0.5 shows decreased tetragonal strain and Curie temperature. Relationship of polarization with lattice response is discussed.

The homopolymer of aniline (An) and its copolymer with 8-anilino-1-napthalene suplhonic acid (8-ANSA) was synthesized by chemical oxidative as well as electrochemical polymerization process in the presence of para-toluene sulphonic acid (PTSA) as a dopant. The spectral, thermal, morphological and electrochemical properties of PTSA doped polyaniline and its copolymer (An-co-8-ANSA) were studied and compared to elucidate the effect of the inclusion of 8-ANSA in the copolymer feed. The resultant copolymer showed better solubility and processibility but this approach usually results in the lowering of conductivity, hence the ratio of aniline and 8-ANSA in the copolymer feed was selected to 80:20. The room temperature conductivity of the PTSA doped polyaniline (PANI-PTS) and poly(An-co-8-ANSA) in 80:20 was found to be in the order of 1.74 S/cm to 9.77×10 −1 S/cm, respectively. Conductivity mechanism of charge transport has been investigated in the range 30-300K. In the temperature range 30-70 K, copolymer showed tunneling mechanism. However, above 70 K conductivity attributes to Mott ' s variable range hopping (VRH) mechanism. The electrochemical behaviour of the polymers was studied by cyclic voltametry. The structure of the copolymer is characterized by 1 H NMR spectroscopy, UV-visible and FTIR spectroscopy. Electrostatic charge dissipation (ESD) of the conducting copolymer blend was also studied by blending of 1% of PTSA doped polyaniline and poly(aniline-co-8-ANSA) with LDPE which shows a static decay time of 0.1 to 0.25 sec on dissipating the charge from 5000 to 500 V.

xV 2 O 5 Á ð100 À xÞ½P 2 O 5 Á Li 2 O glass system, with 0 < x 50 mol%, was prepared and investigated by EPR method. For low content of V 2 O 5 all the spectra present a hyperfine structure typical for isolated V 4+ ions. With the increasing of V 2 O 5 content, the EPR absorption signal showing hyperfine structure is superposed by a broad line without hyperfine structure characteristic for clustered ions. At high V 2 O 5 content, the vanadium hyperfine structure disappears and only the broad line can be observed in the spectra.

Nanoscale composites of polyaniline (PANI) and vanadium oxide (V 2 O 5 ) were assembled via the electrostatic layer-by-layer (LBL) technique, with a thickness per bilayer of 2.5 nm. Interactions between PANI and V 2 O 5 are maximized in comparison to the usual xerogel films due to the nanostructured nature of the LBL films, in which V 2 O 5 causes PANI to be oxidized. This has been demonstrated in Raman spectroscopy measurements and is consistent with electrochemical data. These strong interactions make the LBL film to display a color that is different from the colors of the individual materials. Furthermore, they promote a cooperative effect that enhances the charge storage capability of the films, with a total charge of 2.25 mC cm -2 for the PANI/ V 2 O 5 LBL films, in comparison with 1.86 mC cm -2 for the sum of the isolated contributions from PANI and V 2 O 5 .

We present in this study the electrochemical properties of poly(3,4-dimethylthiophene) (PDMT) in comparison with poly(3-methylthiophene) (P3MT). The electropolymerizations were carried out at constant current densities (j = +2.5 mA/cm 2 ) in 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI) and N-butyl-N-methylpyrrolidiniumbis(trifluoromethanesulfonyl)imide (PYRTFSI). The electrochemical stability of PDMT has been considerably enhanced with the use of ionic liquids with a cyclability up to 1500 cycles in EMITFSI compared to only 100 cycles in acetonitrile and 0.1 M tetraethylammoniumtetrafluoroborate (TBATFB). PDMT exhibits better electrochemical storage properties based on the measure of its specific capacitance (287 F/g in EMITFSI) compared to P3MT (190 F/g). The electrochemical reduction of doped PDMT is not complete as attested by UV-visible spectroscopic studies which showed the dual presence of transition bands of both neutral and polaronic species even after dedoping. This behaviour affects the doping/dedoping process of this polymer with loss of electroactivity whatever the ionic liquid used. Then, we performed the copolymerization at constant current densities from feed solutions containing the two monomers at different ratios. The evolution of the composition has been correlated to the continuous modulation of both electrochemical and optical properties. The oxidation potential of copolymers and the optical gap evolve according to the amount of DMT in the feed solution. Cyclic voltamperometry and UV-visible spectroscopy have confirmed that whatever the electrolyte (i) the copolymers have random composition and (ii) more DMT units are incorporated in the copolymer than DMT units initially present in the feed solution. The specific capacitance C m of the copolymers increases with the amount of DMT from 190 F/g to 287 F/g in EMITFSI and from 230 F/g to 279 F/g in PYRTFSI at 30 • C. The cyclability of copolymers is also improved compared to PDMT homopolymer. Therefore, this class of material is interesting in the field of electrochemical devices regarding the tunability of their electrochemical properties.

Novel ultrasound backing materials based on polymer composites with improved dimensional stability and low coefficient of thermal expansion are being developed and analyzed. For this purpose a filled epoxy resin (Stycast 1265 ), a commonly used backing material, was considered reference material and polyurethane composites (PU 2305 , PU 2350 ) were proposed as better alternatives. When compared to the reference, the PU 2350 filled with a mixture of Al 2 O 3 and tungsten exhibited an approximately 15 times lower glassy transition temperature and a 2.5 time lower longitudinal thermal expansion at 20°C. This ensures that within the entire operational temperature range the backing material is flexible, minimizing the thermal stresses induced onto transducer elements soldered joints and piezoceramic core. For the same material, the attenuation at 5 MHz was similar to the reference material while at 7 and 8.5 MHz it was 33% and 54% higher respectively. From these analyses it is concluded that the newly developed polyurethane composites outperform the reference backing with respect to the thermal dimensional stability as well as to the damping properties. An integrated rigorous mechano-acoustical approach is being proposed as an appropriate passive material design path. It can be easily extended to any other passive materials used for ultrasound transducer conception.

In this paper, some theoretical attenuation parameters was calculated for shields made up of composite materials basis polymer (Epoxy) with added materials (C,Ni,PbO,Bi) with different concentrations (10,20,30,40,50)wt% , where the effect of concentrations variation on the attenuation coefficients values , effective atomic number and shields density has been studying. The computer program code X-Com was used to calculate the attenuation parameter values at different energies (0.662,1.173,1.332)MeV .Results shows that there is a clear change in the values of these parameters with the change of concentration ratios.

We present in this study the electrochemical properties of poly(3,4-dimethylthiophene) (PDMT) in comparison with poly(3-methylthiophene) (P3MT). The electropolymerizations were carried out at constant current densities (j = +2.5 mA/cm 2 ) in 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI) and N-butyl-N-methylpyrrolidiniumbis(trifluoromethanesulfonyl)imide (PYRTFSI). The electrochemical stability of PDMT has been considerably enhanced with the use of ionic liquids with a cyclability up to 1500 cycles in EMITFSI compared to only 100 cycles in acetonitrile and 0.1 M tetraethylammoniumtetrafluoroborate (TBATFB). PDMT exhibits better electrochemical storage properties based on the measure of its specific capacitance (287 F/g in EMITFSI) compared to P3MT (190 F/g). The electrochemical reduction of doped PDMT is not complete as attested by UV-visible spectroscopic studies which showed the dual presence of transition bands of both neutral and polaronic species even after dedoping. This behaviour affects the doping/dedoping process of this polymer with loss of electroactivity whatever the ionic liquid used. Then, we performed the copolymerization at constant current densities from feed solutions containing the two monomers at different ratios. The evolution of the composition has been correlated to the continuous modulation of both electrochemical and optical properties. The oxidation potential of copolymers and the optical gap evolve according to the amount of DMT in the feed solution. Cyclic voltamperometry and UV-visible spectroscopy have confirmed that whatever the electrolyte (i) the copolymers have random composition and (ii) more DMT units are incorporated in the copolymer than DMT units initially present in the feed solution. The specific capacitance C m of the copolymers increases with the amount of DMT from 190 F/g to 287 F/g in EMITFSI and from 230 F/g to 279 F/g in PYRTFSI at 30 • C. The cyclability of copolymers is also improved compared to PDMT homopolymer. Therefore, this class of material is interesting in the field of electrochemical devices regarding the tunability of their electrochemical properties.

Some of physical properties of polyvinyl alcohol dissolves in distilled water had been studied before and after adding different weights of copper (II) chloride (CuCl 2 ), the Rheological properties shows that the densities variation are intangible and shear viscosity are responsible for reducing velocity, bulk modulus and transmittance the absorption coefficient of ultrasonic waves and relaxation amplitude are increasing with adding copper (II) chloride because there will be more molecules in solution and this lead to more attenuation against wave propagation

Electrocopolymerization of aniline (ANI) with o-chloro aniline (OCA) was carried out using pulse potentiostatic method (PPSM). The polymeric films were grown on the surface of working electrode for various experimental conditions. Cyclic voltammograms of the deposited films were recorded under all the conditions. A growth equation was deduced as Growth = k[ANI][OCA] −1 , where k is the rate constant for copolymer deposition, correlating the charge associated with the redox processes of the polymeric films with the experimental conditions. Formation of the copolymer with the mixture of monomers in the feed was ascertained by a critical comparison of the results obtained with the polymerization of the individual monomers, ANI and OCA, independently. The surface parameters like surface excess and thickness of the films were evaluated. Further characterization of the copolymer, poly(ANI-co-OCA) was done through conductivity measurements, FTIR and UV-VIS spectroscopic techniques.

This article reports the synthesis and characterization of copolymers based on aniline and substituted anilines by using dodecylbenzene sulfonic acid as a dopant. The copolymers were soluble in organic solvents, such as methanol, ethanol, isopropanol, N-methylpyrrolidinone, dimethylsulphoxide, and have conductivity of the order of 1.5 to 10 À7 S/cm depending upon the monomer ratios and extent of dopant used. The effect of substituents like 2methyl, 2-ethyl, and 2-isopropyl groups on the electrochemical, conductivity, thermal stability, solubilization, and spectroscopic behavior of the copolymers has been evaluated.

The redox dye Toluidine Blue (TB), adsorbed and electropolymerized at a roughened gold electrode, has been studied by Raman spectroscopy at λex of 676.4nm in an electrochemical cell. Most of the spectral bands have been assigned based on density functional theory (DFT) calculations. The number and position of the bands, as well as their intensity depend on electrode potential and

Polyaniline powder and films can be modified by nucleophilic addition of arenesulphinic acids to oxidized forms of polyaniline. The FTIR spectra of modified polymers suggest the formation of sulphone and/or sulphonamide moieties linked to the polymer backbone. The modification degree increases with the increasing of the oxidation state of the polymer. The addition decreases significantly at pH above 7. It is proposed a mechanism of nucleophilic addition, which explains the effect of the oxidation state of the polymer and pH of the solution. The modification increases the solubility of the polymers in common organic solvents. The modification reaction seems to provide a simple pathway to the incorporation of organic moieties to polyaniline backbone.

In this study, the samples have been prepared by adding rice shell to the poly vinyl alcohol and poly vinyl acetate with different weight percentages (0,5,10,15.20.25.30 and 35) wt%. The A.C electrical properties show that the dielectric constant and dielectric loss of the composites decrease with increasing the frequency of applied electrical field and they increase with the increase of the concentration of the rice shell . The A.C electrical conductivity increases with increasing the concentration of rice shell, increases with the increase frequency, and almost constant at high frequency.

The palm fiber –PVA composite polymer membrane were prepared by solution
casting method with different ratios of concentration in order to study the
ultrasonic frequency affect on mechanical properties of this composite.
Ultrasonic pulse technique of variable frequency (25,30,35,40,45 and 50 kHz)
were performed ,some properties such as ultrasonic velocity, acoustic
impedance ,bulk modulus ,transmittance and viscosity are decreasing with
increasing frequency while absorption coefficient, relaxation time,
compressibility and relaxation amplitude are increasing with increasing
frequency .results shows that ultrasonic wave made degradation to the
randomly coiled polymer chains ,when ultrasonic frequency increase there are
more degradation that increasing the number of un-tie chains as a results of
absorbing composite ultrasonic waves ,for this reason we pointed that palm
fiber-PVA composite as a good ultrasonic absorber.

The PVA/TiO2 composite polymer membranes were prepared by a sol-Gel casting method, the weight of PVA is constant (1gm) while the TiO2 powder ratios were (0.01, 0.02, 0.03, 0.04, 0.05) gm. In order to evaluate the mechanical properties of PVA/TiO2 composite the ultrasonic measurements were performed at the samples , these properties are ultrasonic velocity, compressibility, acoustic impedance, relaxation time, bulk modulus, shear viscosity and density were analyzed at different frequencies (25,30,35,40) kHz , another acoustic mechanical properties were measured and calculated at a same time such as the ultrasonic wave amplitude before and after absorption by composite were measured using oscilloscope ,then we calculated absorption coefficient and transmittance. It was found that there is significant relationship between ultrasonic velocity and material properties also results show that adding TiO2 effect on the absorption of the ultrasonic waves inside the composites samples.

The PVA-Palm fiber composite polymer membranes were prepared by sol-gel
casting method with different ratios of concentration, in order to study the mechanical
properties of these composite ultrasonic measurements of variable frequencies
(25,30,35,40,45 and 50 kHz) were performed , these properties are ultrasonic velocity
,density ,compressibility ,specific acoustic impedance ,relaxation time, relaxation
amplitude , bulk modulus, shear viscosity ,absorption coefficient and transmittance. Results
shows that all these properties were decreasing with concentration of palm fiber in
composite ; so palm powder keep the degradations polymer chain isolated and their roots
not interact again to forming entanglement interactions, this reason made these vales
reduced except that scattering were dominant so we pointed that this composite more
effective to reflect and scattered ultrasonic waves.

Electrical properties were studied for Pectin/PVA graphene composites films and the effect of aqueous interaction on their properties. The conductivity and the dielectric constant of this composite are important because Polysaccharide like pectin is increasingly being used in biomedical applications and as nanoparticles coating materials. The Dielectric and conductivity of composite films were compared in dry and wet condition the differences in the results were attributed to the water molecules and the hydrogen bond which connect the three composite compounds (Pectin, PVA and Graphene) together. These connections were allowed the hydrogen and hydroxyl group's migrations in the composite super molecules. On the other hand, graphene was prepared and with different techniques like Ft-IR, XRD, SEM and AFM characterized.

Glasses with composition x Bi 2 O 3 ·(30 2 x)M 2 O·70B 2 O 3 (M ¼ Li, Na) containing 2 mol% V 2 O 5 have been prepared over the range 0 # x # 15 (x is in mol%). The electron paramagnetic resonance spectra of VO 2þ of these glasses have been recorded in the X-band (<9.3 GHz) at room temperature (RT < 300 K). Spin Hamiltonian parameters, g k ; g ' ; A k ; A ' ; dipolar hyperfine coupling parameter, P; and Fermi contact interaction parameter, K; have been calculated. The molecular orbital coefficients, a 2 and g 2 ; have been calculated by recording the optical transmission spectra. In x Bi 2 O 3 ·(30 2 x)Li 2 O·70B 2 O 3 glasses there is decrease in the tetragonality of the V 4þ O 6 complex for x up to 6 mol% whereas for x $ 6 mol%, tetragonality increases. In x Bi 2 O 3 ·(30 2 x)Na 2 O·70B 2 O 3 glasses there is increase in the tetragonality of the V 4þ O 6 complex with increasing x: The 3d xy orbit expands with increase in Bi 2 O 3 :M 2 O ratio. Values of the theoretical optical basicity, L th ; have also been reported. The DC conductivity increases with increase in temperature. The order of conductivity is 10 25 ohm 21 m 21 at low temperature and 10 23 ohm 21 m 21 at high temperature. The DC conductivity decreases and the activation energy increases with increase in Bi 2 O 3 :M 2 O ratio. q

Copolymers of aniline and 2-ethylaniline can be easily formed by electrochemical or chemical oxidation in acidic medium, but the composition of the polymeric chain differs from the composition of the synthesis solution. Copolymers formed from precursor solutions containing less than 30% (in moles) of 2-ethylaniline show intermediate properties between those of the homopolymers, and these properties vary gradually with the amount of 2-ethylaniline units in the copolymeric chain. The properties of those copolymers have been studied by UV Á/Vis and resonance Raman spectroscopies, cyclic voltammetry, two-probe conductivity and solubility measurements. Results obtained by these techniques corroborate the formation of a block copolymeric material. #