scholarly journals Microstructures and Electrical Properties of HPMC/PVP Polymer Blend Films Complex with Ferric Chloride (FeCl3)

2014 ◽  
Vol 11 (2) ◽  
pp. 153-158
Author(s):  
H Ananda ◽  
T Urs ◽  
Y Prakash ◽  
K Hemalatha ◽  
H Somashekarappa ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Structural Modification ◽  
Dopant Concentration ◽  
Methyl Cellulose ◽  
Vinyl Pyrrolidone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blend Films ◽  
Poly Vinyl Pyrrolidone ◽  
Microstructural Studies

Microstructural studies on FeCl3 doped Hydroxypropyl methyl cellulose (HPMC)/Poly vinyl pyrrolidone (PVP) blend films were carried out using X-Ray diffraction studies. The XRD data revealed that the crystalline regions of the HPMC/PVP blend film decreases up to a certain percentage of FeCl3 and then increases. Electrical conductivity studies on these doped films suggest complex formation due to doping which affects microstructure and also ac conductivity of polymer films. All these results were analyzed and explained on the basis of micro structural modification of HPMC/PVP blends as function of dopant concentration.

Preparation of PCL/PVP/Ag Nanofiber Membranes by Electrospinning Method

2012 ◽  
Vol 268-270 ◽  
pp. 580-583 ◽  
Author(s):  
Yong Tang Jia ◽  
Cui Wu ◽  
Feng Chun Dong ◽  
Gang Huang ◽  
Xian Hua Zeng
Keyword(s):  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Composite Nanofibers ◽  
Average Diameter ◽  
Vinyl Pyrrolidone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Nanofiber Membranes ◽  
Poly Vinyl Pyrrolidone

The composite nanofiber membranes of poly (ε-caprolactone)/poly(vinyl pyrrolidone) (PCL/PVP) containing silver nanoparticles were prepared by electrospinning method. The morphology of composite nanofibers was characterized by scanning electron microscopy (SEM). The silver nanoparticles on the electrospun fibers were characterized by X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The contact angle and water uptake of PCL/PVP/Ag nanofiber membranes were measured. The SEM photos indicated that the average diameter of the fibers was significantly decreased with the addition of silver nanoparticles. The X-Ray images showed that Ag nanoparticles were distributed on the surface of nanofiber membranes. When the PVP mole ratio was higher than 15%, the nanofiber membranes showed good hydrophilic property. The PCL/PVP/Ag nanofiber membranes could be applied to prepare wound dressing.

scholarly journals ENHANCEMENT OF ELECTRICAL CONDUCTIVITY IN POLYVINYL ALCOHOL FILMS BY DOPING WITH Nd3+IONS

2017 ◽  
Vol 5 (4RAST) ◽  
pp. 87-91
Author(s):  
Vijaya Kumar
Keyword(s):  
Electrical Conductivity ◽  
Polyvinyl Alcohol ◽  
Dopant Concentration ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Casting Method ◽  
Xrd Pattern ◽  
X Ray ◽  
Solution Casting Method ◽  
Polyvinyl Alcohol Films

The electrical properties of polyvinyl alcohol (PVA) films have been improved pronouncedly by doping with Neodymium (III) nitrate hexahydrate.  Pure PVA and PVA: Nd3+ films have been prepared by solution casting method. Both type of films were characterized by X-ray diffraction technique for structural studies. XRD pattern shows the appreciable shift of 2Ө towards higher value with increase in Nd3+ concentration. This signifies the presence Nd3+ dopant in polymer matrix. Further direct current electrical conductivity (σ) of Nd3+ doped PVA films in the temperature range 500C-1600C has been studied using four probe techniques. For a given concentration σ increases with increase in temperature and with dopant concentration. At 1200C, conductivity of PVA: Nd3+ (10 mol %) film is 7.116 μΩ-1cm-1, PVA: Nd3+ (15 mol %) film is 11.176 μΩ-1cm-1, PVA: Nd3+ (20 mol %) film is 17.418 μΩ-1cm-1 and PVA: Nd3+ (25 mol %) film is 23.740 μΩ-1cm-1. This result indicated the enhancement of the electrical conductivity of PVA films with Nd3+ concentration.

Electrospun Polythiophene Nanofibers and Their Applications for Organic Solar Cells

2011 ◽  
Vol 1303 ◽  
Author(s):  
Surawut Chuangchote ◽  
Michiyasu Fujita ◽  
Takashi Sagawa ◽  
Susumu Yoshikawa
Keyword(s):  
Organic Solar Cells ◽  
Mixed Solvent ◽  
Bulk Heterojunction ◽  
Photovoltaic Cells ◽  
Selective Extraction ◽  
Vinyl Pyrrolidone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wrinkled Surface ◽  
Poly Vinyl Pyrrolidone

ABSTRACTPoly(3-hexylthiophene) (P3HT) nanofibers were fabricated with an association of poly(vinyl pyrrolidone) (PVP) by electrospinning. A mixture of P3HT/PVP in a mixed solvent of chlorobenzene and methanol was electrospun to form composite fibers with 60 nm - 2 μm in diameter, followed by getting rid of PVP by selective extraction. After extraction, pure P3HT nanofibers were obtained as a spindle-like structure with wrinkled surface. The nanofibers obtained exhibit specific features of strong interchain contribution as investigated by UV-vis, fluorescence spectroscopic, X-ray diffraction (XRD), and photo-electron investigations. Bulk heterojunction P3HT:PCBM nanofibers with ~200 nm in diameters were also successfully fabricated by using the same technique. The preliminary results from the study of P3HT:PCBM nanofiber-based photovoltaic cells with conversion efficiency over 0.2% could be achieved.

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

scholarly journals Investigation and Modeling of the Electrical Conductivity of Graphene Nanoplatelets-Loaded Doped-Polypyrrole

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1034
Author(s):  
Oladipo Folorunso ◽  
Yskandar Hamam ◽  
Rotimi Sadiku ◽  
Suprakas Sinha Ray ◽  
Neeraj Kumar
Keyword(s):  
Electrical Conductivity ◽  
Structural Changes ◽  
Spherical Shape ◽  
Graphene Nanoplatelets ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Energy Storage Applications ◽  
Electrical Conductivity Data

In this study, a hybrid of graphene nanoplatelets with a polypyrrole having 20 wt.% loading of carbon-black (HGPPy.CB20%), has been fabricated. The thermal stability, structural changes, morphology, and the electrical conductivity of the hybrids were investigated using thermogravimetric analyzer, differential scanning calorimeter, X-ray diffraction analyzer, scanning electron microscope, and laboratory electrical conductivity device. The morphology of the hybrid shows well dispersion of graphene nanoplatelets on the surface of the PPy.CB20% and the transformation of the gravel-like PPy.CB20% shape to compact spherical shape. Moreover, the hybrid’s electrical conductivity measurements showed percolation threshold at 0.15 wt.% of the graphene nanoplatelets content and the curve is non-linear. The electrical conductivity data were analyzed by comparing different existing models (Weber, Clingerman and Taherian). The results show that Taherian and Clingerman models, which consider the aspect ratio, roundness, wettability, filler electrical conductivity, surface interaction, and volume fractions, closely described the experimental data. From these results, it is evident that Taherian and Clingerman models can be modified for better prediction of the hybrids electrical conductivity measurements. In addition, this study shows that graphene nanoplatelets are essential and have a significant influence on the modification of PPy.CB20% for energy storage applications.

scholarly journals PREPARATION AND CHARACTERIZATION OF POLY (VINYL ALCOHOL)–POLY (VINYL PYRROLIDONE) MUCOADHESIVE BUCCAL PATCHES FOR DELIVERY OF LIDOCAINE HCL

2018 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Napaphak Jaipakdee ◽  
Thaned Pongjanyakul ◽  
Ekapol Limpongsa
Keyword(s):  
Vinyl Alcohol ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Casting Technique ◽  
In Vitro Permeation ◽  
Lidocaine Hcl ◽  
Poly Vinyl Pyrrolidone

Objective: The objectives of this study were to prepare and characterize a buccal mucoadhesive patch using poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) as a mucoadhesive matrix, Eudragit S100 as a backing layer, and lidocaine HCl as a model drug.Methods: Lidocaine HCl buccal patches were prepared using double casting technique. Molecular interactions in the polymer matrices were studied using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and X-ray diffractometry. Mechanical and mucoadhesive properties were measured using texture analyzer. In vitro permeation of lidocaine HCl from the patch was conducted using Franz diffusion cell.Results: Both of the free and lidocaine HCl patches were smooth and transparent, with good flexibility and strength. ATR-FTIR, DSC and X-ray diffractometry studies confirmed the interaction of PVA and PVP. Mechanical properties of matrices containing 60% PVP were significantly lower than those containing 20% PVP (*P<0.05). Mucoadhesive properties had a tendency to decrease with the concentration of PVP in the patch. The patch containing 60% PVP had significantly lower muco-adhesiveness than those containing 20% PVP (*P<0.05). In vitro permeation revealed that the pattern of lidocaine HCl permeation started with an initial fast permeation, followed by a slower permeation rate. The initial permeation fluxes follow the zero-order model of which rate was not affected by the PVP concentrations in the PVA/PVP matrix.Conclusion: Mucoadhesive buccal patches fabricated with PVA/PVP were successfully prepared. Incorporation of PVP in PVA/PVP matrix affected the strength of polymeric matrix and mucoadhesive property of patches.

Dehydration and decomposition of pyrophyllite at high pressures: electrical conductivity and X-ray diffraction studies to 5 GPa

1997 ◽  
Vol 34 (6) ◽  
pp. 875-882 ◽  
Author(s):  
Tara L. Hicks ◽  
Richard A. Secco
Keyword(s):  
Electrical Conductivity ◽  
South African ◽  
Pressure Dependence ◽  
High Pressures ◽  
Ionic Conduction ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Dependence Of Conductivity

The dehydration and decomposition of South African pyrophyllite were studied in the pressure range 2.5–5.0 GPa and in the temperature (T) range 295–1473 K using both in situ electrical conductivity measurements and X-ray diffraction studies on the recovered samples. Activation energies for conduction (Qc) vary in the range 0.02–0.07 eV for T ≤ 500 K where the dominant conduction mode is electronic, and Qc is in the range 1.10–1.28 eV for T ≥ 500 K where ionic conduction dominates. Abrupt changes in the isobaric temperature dependence of conductivity mark the onset of dehydration and subsequent decomposition into kyanite plus quartz–coesite. At 2.5 GPa, South African pyrophyllite forms the dehydroxylate phase at 760 K with a pressure dependence of ~30 K/GPa and complete decomposition follows at 1080 K with a pressure dependence of ~41 K/GPa. The resulting pressure–temperature phase diagram is in very good agreement with many previous studies at 1 atm (101.325 kPa).

scholarly journals Influence of B2O3 doping on synthesis of MgTiO3 ceramics from recycled magnesia-hercynite materials

2021 ◽  
Vol 8 (12) ◽  
pp. 125901
Author(s):  
Xiaodong Jia ◽  
Shuo Mao ◽  
Lin Tian ◽  
Shujiang Chen ◽  
Guohua Li ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Raw Materials ◽  
Microwave Dielectric Properties ◽  
Synthesis Rate ◽  
Cement Kiln ◽  
X Ray Diffraction ◽  
Optimum Amount ◽  
X Ray ◽  
Microwave Dielectric ◽  
Microstructural Studies

Abstract Herein, magnesium metatitanate (MgTiO3) ceramics were synthesised using recycled magnesia-hercynite (MH) bricks as the raw materials to achieve solid waste reusing of cement kiln refractories. The recycled MH materials were mixed with anatase TiO2 to investigate the effect of addition of doped B2O3 during the synthesis of MgTiO3 ceramics at 1400 °C. Phase compositions and microstructural studies were performed using x-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. In addition, energy-dispersive spectroscopy (EDS) was conducted and the dielectric properties of the samples were studied. Results show that the addition of B2O3 can promote sintering, improve shrinkage, promote densification, stabilise MgTiO3 lattice, and inhibit the formation of MgTiO3. In addition, the presence of appropriate amount of B2O3 can accelerate the material diffusion and result in grain growth through the formation of intercrystalline liquid phase. Results also suggest that an increase in dielectric constant results in a decrease in dielectric loss. It was concluded that 2 wt% was the optimum amount of B2O3 required to obtain the most favourable synthesis rate of MgTiO3 (98.2%). The samples exhibited a maximum density of 3.69 g·cm−3 and excellent microwave dielectric properties at ε r = 18.28 and tanδ = 0.086.

Lateral deformations of a crystal of potassium acid phthalate in an external electric field

2021 ◽  
Vol 54 (5) ◽  
pp. 1317-1326
Author(s):  
Arsen Petrenko ◽  
Nataliya Novikova ◽  
Alexander Blagov ◽  
Anton Kulikov ◽  
Yury Pisarevskii ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Electric Field ◽  
External Electric Field ◽  
Applied Field ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

The anisotropy of deformations in potassium acid phthalate crystals arising under the action of an external electric field up to 1 kV mm−1 applied along the [001] polar axis was studied using X-ray diffraction methods at room temperature. Electrical conductivity was measured and rocking curves for reflections 400, 070 and 004 were obtained by time-resolved X-ray diffractometry in Laue and Bragg geometries. Two saturation processes were observed from the time dependences of the electrical conductivity. A shift in the diffraction peaks and a change in their intensity were found, which indicated a deformation of the crystal structure. Rapid piezoelectric deformation and reversible relaxation-like deformation, kinetically similar to the electrical conductivity of a crystal, were revealed. The deformation depended on the polarity and strength of the applied field. The deformation was more noticeable in the [100] direction and was practically absent in the [001] direction of the applied field. X-ray diffraction analysis revealed a disordered arrangement of potassium atoms, i.e. additional positions and vacancies. The heights of potential barriers between the positions of K+ ions and the paths of their possible migration in the crystal structure of potassium acid phthalate were determined. The data obtained by time-resolved X-ray diffractometry and X-ray structure analysis, along with additional electrophysical measurements, allow the conclusion that the migration of charge carriers (potassium cations) leads to lateral deformation of the crystal structure of potassium phthalate in an external electric field.

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