FACILE PREPARATION AND CHARACTERIZATION OF GRAPHENE NANOSHEET/POLYANILINE NANOFIBER THERMOELECTRIC COMPOSITES

2013 ◽  
Vol 06 (05) ◽  
pp. 1340002 ◽  
Author(s):  
YONG DU ◽  
KEFENG CAI ◽  
SHIRLEY ZHIQI SHEN

Graphene nanosheet (GNs)/polyaniline (PANI) nanofiber composites were prepared by oxidative polymerization of aniline in a GNs dispersed 1 mol/L HCl solution. The phase composition of the composites was analyzed by Fourier Transform Infrared Spectroscopy and X-ray Diffraction. The thermoelectric properties of the composite powders, after cold pressing into pellets, were measured at room temperature. As the content of GNs increased from 0 to 40 wt.%, the electrical conductivity and Seebeck coefficient of the composite pellets increased simultaneously; especially the electrical conductivity increased dramatically from 15.4 to 120.1 S/cm. The highest power factor (~ 394.4 × 10-8 Wm-1K-2) was obtained from the 40 wt.% GNs/PANI composite sample, which is ~200 times as high as that of HCl -doped PANI.

2017 ◽  
Vol 62 (2) ◽  
pp. 1219-1223 ◽  
Author(s):  
M. Thuyet-Nguyen ◽  
W.J. Kim ◽  
J.-C. Kim ◽  

AbstractIn this study, Ni-CNT powders and colloids were synthesized via the Electrical explosion of wire (EEW) in different liquid conditions. The influence of ambient solvents (D.I. Water, ethanol, methanol, acetone and ethylene-glycol) on characteristics of the as-synthesized Ni-CNT was investigated. The morphology and size were observed by field emission scanning electron microscopy (FE-SEM). The Ni particles were spherical or near spherical shape. The phase of the composite powders analyzed via X-ray diffraction demonstrate the presence of CNTs in composite powders is not affect the structure of Ni. However, the phase of the composites was changed based on the changing of liquid conditions. Stability of colloids was investigated by Turbiscan technique. Magnetic properties were also investigated by Vibrating sample magnetometer (VSM) at room temperature. The as-synthesized composite powders revealed a ferromagnetic characteristic material.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3502
Author(s):  
Fangzhou Song ◽  
Masayoshi Uematsu ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao ◽  
Shigeomi Takai

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.


2000 ◽  
Vol 5 (S1) ◽  
pp. 412-424
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.


1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  

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.


Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 28
Author(s):  
Kriti Pathak ◽  
Chandan Nandi ◽  
Jean-François Halet ◽  
Sundargopal Ghosh

Synthesis, isolation, and structural characterization of unique metal rich diamagnetic cobaltaborane clusters are reported. They were obtained from reactions of monoborane as well as modified borohydride reagents with cobalt sources. For example, the reaction of [Cp*CoCl]2 with [LiBH4·THF] and subsequent photolysis with excess [BH3·THF] (THF = tetrahydrofuran) at room temperature afforded the 11-vertex tricobaltaborane nido-[(Cp*Co)3B8H10] (1, Cp* = η5-C5Me5). The reaction of Li[BH2S3] with the dicobaltaoctaborane(12) [(Cp*Co)2B6H10] yielded the 10-vertex nido-2,4-[(Cp*Co)2B8H12] cluster (2), extending the library of dicobaltadecaborane(14) analogues. Although cluster 1 adopts a classical 11-vertex-nido-geometry with one cobalt center and four boron atoms forming the open pentagonal face, it disobeys the Polyhedral Skeletal Electron Pair Theory (PSEPT). Compound 2 adopts a perfectly symmetrical 10-vertex-nido framework with a plane of symmetry bisecting the basal boron plane resulting in two {CoB3} units bridged at the base by two boron atoms and possesses the expected electron count. Both compounds were characterized in solution by multinuclear NMR and IR spectroscopies and by mass spectrometry. Single-crystal X-ray diffraction analyses confirmed the structures of the compounds. Additionally, density functional theory (DFT) calculations were performed in order to study and interpret the nature of bonding and electronic structures of these complexes.


2014 ◽  
Vol 625 ◽  
pp. 661-664
Author(s):  
Chen Chuang Lok ◽  
Yin Fong Yeong

In the present work, ZIF-8/6FDA-durene mixed matrix membranes (MMMs) were synthesized and characterized. ZIF-8 nanocrystals, which were used as the inorganic filler, were synthesized using rapid room-temperature synthesis method whereas 6FDA-durene polyimide was synthesized by polycondensation method followed by chemical imidization. Pure and 6FDA-durene membranes loaded with 5 wt%, 10 wt% and 15 wt% of ZIF-8 were fabricated. The structural properties and morphology of the resultant membranes were characterized by using X-ray Diffraction (XRD) and Field emission scanning electron microscope (FESEM) . The EDX images showed that ZIF-8 particles agglomerated in the polymer matrix. However, no phase separation was observed for all resultant MMMs.


2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Yan Li ◽  
Chuan-Sheng Liu ◽  
Yun-Ling Zou

AbstractZnO nano-tubes (ZNTs) have been successfully synthesized via a simple hydrothermal-etching method, and characterized by X-ray diffraction, field emission scanning electron microscopy and room temperature photoluminescence measurement. The as-synthesized ZNTs have a diameter of 500 nm, wall thickness of 20–30 nm, and length of 5 µm. Intensity of the plane (0002) diffraction peak, compared with that of plane (10$$ \bar 1 $$0) of ZNTs, is obviously lower than that of ZnO nano-rods. This phenomenon can be caused by the smaller cross section of plane (0002) of the nano-tubes compared with that of other morphologies. On basis of the morphological analysis, the formation process of nano-tubes can be proposed in two stages: hydrothermal growth and reaction etching process.


2017 ◽  
Vol 31 (02) ◽  
pp. 1750006 ◽  
Author(s):  
Mohammad Hossein Ghorbani ◽  
Abdol Mahmood Davarpanah

Manganese oxides are of more interest to researchers because of their ability as catalysts and lithium batteries. In this research, MnO2nanowires with diameter about 45 nm were synthesized by sol–gel method at room temperature (RT). Effect of increasing the annealing temperature from 400[Formula: see text]C to 600[Formula: see text]C on crystalline structure of nanostructure were studied and average crystallite size was estimated about 22 nm. X-ray Diffraction (XRD) method, Energy-Dispersive X-ray Diffraction (EDXD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) were used to characterize the nanowires of MnO2.


1999 ◽  
Vol 595 ◽  
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  

AbstractWe report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.


2020 ◽  
Vol 307 ◽  
pp. 339-344
Author(s):  
Ishak Qayyum Afiqah ◽  
Nik Aziz Nik Ali ◽  
Abd Majid Siti Nurhaziqah ◽  
Hasiah Salleh

Age of monstrous amount of underutilized marine processing byproducts has been perceived as waste and many effort were given to utilize these materials in various application. With an incredible number of study on these byproducts, some compound were identified and apply for human utilization. Hydroxyapatite (HAp) is the main inorganic calcium phosphate mineral with excellent osteoconductivity, good bioactivity and biocompatibility. The production of HAp powder from synthetic process involves many chemicals with complicated procedures. Due to this matter, the raw HAp powder was extracted from natural sources selayang fish bones. Extortion process started with boiling fish bones to eliminate adherent fish meats. After calcination process fish bone were dried in room temperature before crushed by using grinder to obtain the powder. Next, the powder undergo calcination process at 900°C for 5 hours. The characterization of raw HAp was done via X-ray Diffraction, Fourier Transform Infrared Spectometer, Scanning Electron Microscopy, and Thermogravimetric analysis.


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