Synthesis and Characterization of Novel Multipods-Branched Cd-Se-S Micro-/Nano-Structures

2018 ◽  
Vol 281 ◽  
pp. 819-824
Author(s):  
Hong Li ◽  
Yu Zhang ◽  
Cheng Biao Wang ◽  
Zhi Jian Peng ◽  
Xiu Li Fu
Keyword(s):  
High Purity ◽  
Gas Flow ◽  
Hexagonal Structure ◽  
Molar Ratio ◽  
Good Crystallinity ◽  
Microstructure Examination ◽  
Evaporation Source ◽  
Protective Gas ◽  
Ar Gas

Novel multipods-branched Cd-Se-S micro-/nanostructures (MNSs) were successfully prepared in a tube furnace by thermal evaporation under atmospheric pressure through using high-purity CdS and CdSe mixture powder with a molar ratio of 1:1 as evaporation source, high-purity Ar gas as carrier and protective gas, and mica wafer as substrate. Under the optimum condition, the evaporation temperature was 1100 °C, Ar gas flow rate was 200 sccm, and the distance between the evaporation source and substrate was 22 cm. The microstructure examination revealed that the length of the obtained branches was up to tens of microns and the diameter of the branches was of a few microns. The composition and crystal structure analyses indicated that, the chemical composition of the multipods-branched Cd-Se-S MNSs was CdSe0.86S0.14, which had a hexagonal structure and good crystallinity. The photoluminescence spectrum at room temperature displays an intrinsic emission peak around 620 nm. In addition, their growth might be controlled by a vapor-solid mechanism.

Hydrogen Production Through Two-Step Water Splitting Using YSZ (Ni,Fe) System for Solar Hydrogen Production

Solar Energy ◽  
2005 ◽  
Author(s):  
Hideyuki Ishihara ◽  
Hiroshi Kaneko ◽  
Tsutomu Yokoyama ◽  
Akinori Fuse ◽  
Noriko Hasegawa ◽  
...  
Keyword(s):  
Solid Solution ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Gas Flow ◽  
Molar Ratio ◽  
Iron Ions ◽  
Solar Hydrogen ◽  
Solar Hydrogen Production ◽  
Ar Gas ◽  
Splitting Process

The two-step water splitting with the solid solution of YSZ (Yttrium stabilized Zirconia) and Ni-ferrite (NiFe2O4) was studied for solar hydrogen production. The sample of YSZ/Ni-ferrite solid solution was prepared by calcination of the mixture of the YSZ balls and Ni-ferrite (NiFe2O4) powder. The two-step water splitting process composed of O2-releasing reaction (T = 1773K) in Ar gas flow and H2-generation reaction (T = 1473K) in Ar gas and steam flow with the YSZ/Ni-ferrite solid solution were repeated ten times, and the molar ratio of the released O2 gas and the generated H2 gas was nearly equal to 1:2 in each cycle, indicating that the two-step water splitting process proceeded stoichiometrically. The lattice constants of the YSZ/Ni-ferrite solid solution products after each step of the water splitting process were varied, therefore it was assumed that the oxidation and reduction of the iron ions proceeded in the YSZ phase. It is confirmed that the YSZ/Ni-ferrite was the solid solution and reactive ceramics of high thermal stability. The contents of iron ions determined by the atomic absorption spectroscopy indicated that the YSZ/Ni-ferrite solid solution heated at 1773K contained the only 36% of iron loaded initially. The generated O2 gas was 42% of the theoretical yield. These suggest that YSZ/Ni-ferrite solid solution is more effective reactive ceramics which has the ability to split water with concentrated solar heat than Ni-ferrite.

High Purity Magnetite Microparticles Directly Derived from Mill Scale via Hydrogen-Reduction Method

2021 ◽  
Vol 1016 ◽  
pp. 286-291
Author(s):  
Autchariya Boontanom ◽  
Piyada Suwanpinij
Keyword(s):  
Flow Rate ◽  
High Purity ◽  
Gas Flow ◽  
Reduction Method ◽  
Hydrogen Reduction ◽  
Reduction Temperature ◽  
Mixed Gas ◽  
Mill Scale ◽  
X Ray ◽  
Ar Gas

This study develops a fast and simple way to produce high purity magnetite (Fe3O4) microparticles from mill scale by using hydrogen reduction with the addition of vapour as a retarding agent. By optimising the reduction temperature and gas flow rate, the characterisations by X-ray diffractometry technique shown that the Fe3O4 fraction of over 93 wt.-% is shown at the reduction temperature of 550 – 650 oC with the flow rate of the 4.5-5.5 mol%H2 + Ar gas + H2O gas mixture from 100 – 200 ml/min. The highest Fe3O4 fraction of over 99 wt.-% can be achieved from the reduction with the mixed gas at 650 oC and the flow rate of 200 ml/min for 4 hour.

Optical characterization of BCN films deposited at various N2/Ar gas flow ratios by RF magnetron sputtering

2011 ◽  
Vol 176 (12) ◽  
pp. 878-882 ◽  
Author(s):  
Vinit O. Todi ◽  
Bojanna P. Shantheyanda ◽  
Ravi M. Todi ◽  
Kalpathy B. Sundaram ◽  
Kevin Coffey
Keyword(s):  
Magnetron Sputtering ◽  
Gas Flow ◽  
Rf Magnetron Sputtering ◽  
Optical Characterization ◽  
Ar Gas

TEM characterization of WSix films

1994 ◽  
Vol 52 ◽  
pp. 848-849
Author(s):  
V. C. Kannan ◽  
S. M. Merchant ◽  
R. B. Irwin ◽  
A. K. Nanda ◽  
M. Sundahl ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Vapor Deposition ◽  
High Purity ◽  
Physical Vapor Deposition ◽  
Thermal Treatments ◽  
Rapid Thermal Anneal ◽  
Tungsten Silicide ◽  
Tem Characterization ◽  
Metal Silicides

Metal silicides such as WSi2, MoSi2, TiSi2, TaSi2 and CoSi2 have received wide attention in recent years for semiconductor applications in integrated circuits. In this study, we describe the microstructures of WSix films deposited on SiO2 (oxide) and polysilicon (poly) surfaces on Si wafers afterdeposition and rapid thermal anneal (RTA) at several temperatures. The stoichiometry of WSix films was confirmed by Rutherford Backscattering Spectroscopy (RBS). A correlation between the observed microstructure and measured sheet resistance of the films was also obtained.WSix films were deposited by physical vapor deposition (PVD) using magnetron sputteringin a Varian 3180. A high purity tungsten silicide target with a Si:W ratio of 2.85 was used. Films deposited on oxide or poly substrates gave rise to a Si:W ratio of 2.65 as observed by RBS. To simulatethe thermal treatments of subsequent processing procedures, wafers with tungsten silicide films were subjected to RTA (AG Associates Heatpulse 4108) in a N2 ambient for 60 seconds at temperatures ranging from 700° to 1000°C.

Electron Microscopy/Diffraction Study of the Ternary Mn-Er-S System

1990 ◽  
Vol 48 (1) ◽  
pp. 76-77
Author(s):  
A. R. Landa Canovas ◽  
L.C. Otero Diaz ◽  
T. White ◽  
B.G. Hyde
Keyword(s):  
Electron Microscopy ◽  
Gas Flow ◽  
Graphite Crucible ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Alumina Crucible ◽  
X Ray ◽  
Intermediate Phases ◽  
Twin Band ◽  
Ar Gas

X-Ray diffraction revealed two intermediate phases in the system MnS+Er2S3,:MnEr2S4= MnS.Er2S3, and MnEr4S7= MnS.2Er2S3. Their structures may be described as NaCl type, chemically twinned at the unit cell level, and isostructural with CaTi2O4, and Y5S7 respectively; i.e. {l13} NaCl twin band widths are (4,4) and (4,3).The present study was to search for structurally-related (twinned B.) structures and or possible disorder, using the more sensitive and appropiate technigue of electron microscopy/diffraction.A sample with nominal composition MnEr2S4 was made by heating Mn3O4 and Er2O3 in a graphite crucible and a 5% H2S in Ar gas flow at 1500°C for 4 hours. A small amount of this material was thenannealed, in an alumina crucible, contained in sealed evacuated silica tube, for 24 days at 1100°C. Both samples were studied by X-ray powder diffraction, and in JEOL 2000 FX and 4000 EX microscopes.

scholarly journals Synthesis and Characterization of Partially Renewable Oleic Acid-Based Ionomers for Proton Exchange Membranes

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 130
Author(s):  
Carlos Corona-García ◽  
Alejandro Onchi ◽  
Arlette A. Santiago ◽  
Araceli Martínez ◽  
Daniella Esperanza Pacheco-Catalán ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Proton Conductivity ◽  
Electrochemical Impedance ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Molar Ratio ◽  
Aromatic Diamines ◽  
Chemical Structures ◽  
Long Chain

The future availability of synthetic polymers is compromised due to the continuous depletion of fossil reserves; thus, the quest for sustainable and eco-friendly specialty polymers is of the utmost importance to ensure our lifestyle. In this regard, this study reports on the use of oleic acid as a renewable source to develop new ionomers intended for proton exchange membranes. Firstly, the cross-metathesis of oleic acid was conducted to yield a renewable and unsaturated long-chain aliphatic dicarboxylic acid, which was further subjected to polycondensation reactions with two aromatic diamines, 4,4′-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline and 4,4′-diamino-2,2′-stilbenedisulfonic acid, as comonomers for the synthesis of a series of partially renewable aromatic-aliphatic polyamides with an increasing degree of sulfonation (DS). The polymer chemical structures were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 19F NMR) spectroscopy, which revealed that the DS was effectively tailored by adjusting the feed molar ratio of the diamines. Next, we performed a study involving the ion exchange capacity, the water uptake, and the proton conductivity in membranes prepared from these partially renewable long-chain polyamides, along with a thorough characterization of the thermomechanical and physical properties. The highest value of the proton conductivity determined by electrochemical impedance spectroscopy (EIS) was found to be 1.55 mS cm−1 at 30 °C after activation of the polymer membrane.

Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder

2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang
Keyword(s):  
Wavelength Range ◽  
High Purity ◽  
Raw Materials ◽  
Formation Rate ◽  
Sol Gel ◽  
Molar Ratio ◽  
Sem And Tem ◽  
Homogeneous Product ◽  
Sol Gel Synthesis ◽  
Calcined Temperature

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.

scholarly journals Biodiesel Production from Melia azedarach and Ricinus communis Oil by Transesterification Process

Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 427 ◽  
Author(s):  
Muhammad Awais ◽  
Sa’ed A Musmar ◽  
Faryal Kabir ◽  
Iram Batool ◽  
Muhammad Asif Rasheed ◽  
...  
Keyword(s):  
Ricinus Communis ◽  
Cost Effective ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Melia Azedarach ◽  
Renewable Fuel ◽  
Animal Fats ◽  
Edible Crops ◽  
American Society

Biodiesel is a renewable fuel usually produced from vegetable oils and animal fats. This study investigates the extraction of oil and its conversion into biodiesel by base-catalyzed transesterification. Firstly, the effect of various solvents (methanol, n-hexane, chloroform, di-ethyl ether) on extraction of oil from non-edible crops, such as R. communis and M. azedarach, were examined. It was observed that a higher concentration of oil was obtained from R. communis (43.6%) as compared to M. azedarach (35.6%) by using methanol and n-hexane, respectively. The extracted oils were subjected to NaOH (1%) catalyzed transesterification by analyzing the effect of oil/methanol molar ratio (1:4, 1:6, 1:8 and 1:10) and varying temperature (20, 40, 60 and 80 °C) for 2.5 h of reaction time. M. azedarach yielded 88% and R. communis yielded 93% biodiesel in 1:6 and 1:8 molar concentrations at ambient temperature whereas, 60 °C was selected as an optimum temperature, giving 90% (M. azedarach) and 94% (R. communis) biodiesel. The extracted oil and biodiesel were characterized for various parameters and most of the properties fulfilled the American Society for Testing and Materials (ASTM) standard biodiesel. The further characterization of fatty acids was done by Gas Chromatography/Mass Spectrometer (GC/MS) and oleic acid was found to be dominant in M. azedarach (61.5%) and R. communis contained ricinoleic acid (75.53%). Furthermore, the functional groups were analyzed by Fourier Transform Infrared Spectroscopy. The results suggested that both of the oils are easily available and can be used for commercial biodiesel production at a cost-effective scale.

scholarly journals Intermediate filaments in non-neuronal cells of invertebrates: isolation and biochemical characterization of intermediate filaments from the esophageal epithelium of the mollusc Helix pomatia.

1985 ◽  
Vol 101 (2) ◽  
pp. 427-440 ◽  
Author(s):  
E Bartnik ◽  
M Osborn ◽  
K Weber
Keyword(s):  
Positive Reaction ◽  
Intermediate Filaments ◽  
Biochemical Characterization ◽  
Helix Pomatia ◽  
Molar Ratio ◽  
Negative Stain ◽  
Epithelial Morphology ◽  
Lower Chordate

To screen invertebrate tissues for the possible expression of intermediate filaments (IFs), immunofluorescence microscopy with the monoclonal antibody anti-IFA known to detect all mammalian IF proteins was used (Pruss, R. M., R. Mirsky, M. C. Raff, R. Thorpe, A. J. Dowding, and B. H. Anderton. 1981. Cell, 27:419-428). In a limited survey, the lower chordate Branchiostoma as well as the invertebrates Arenicola, Lumbricus, Ascaris, and Helix pomatia revealed a positive reaction primarily on epithelia and on nerves, whereas certain other invertebrates appeared negative. To assess the nature of the positive reaction, Helix pomatia was used since a variety of epithelia was strongly stained by anti-IFA. Fixation-extraction procedures were developed that preserve in electron micrographs of esophagus impressive arrays of IFs as tonofilament bundles. Fractionation procedures performed on single cell preparations document large meshworks of long and curvilinear IF by negative stain. These structures can be purified. One- and two-dimensional gels show three components, all of which are recognized by anti-IFA in immunoblotting: 66 kD/pl 6.35, 53 kD/pl 6.05, and 52 kD/pl 5.95. The molar ratio between the larger and more basic polypeptide and the sum of the two more acidic forms is close to 1. After solubilization in 8.5 M urea, in vitro filament reconstitution is induced when urea is removed by dialysis against 2-50 mM Tris buffer at pH 7.8. The reconstituted filaments contain all three polypeptides. The results establish firmly the existence of invertebrate IFs outside neurones and demonstrate that the esophagus of Helix pomatia displays IFs which in line with the epithelial morphology of the tissue could be related to keratin IF of vertebrates.

Sign in / Sign up

Export Citation Format

Share Document