scholarly journals Facile Synthesis and Characterization of Wollastonite Polyindole Composites to Study their Electrical Conductivity Behaviour

2019 ◽  
Vol 62 (2) ◽  
pp. 67-75
Author(s):  
Khalid Javed ◽  
Farah Kanwal ◽  
Saadat Anwar Siddiqi ◽  
Shahid Atiq ◽  
Waheed Mushtaq ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Dc Conductivity ◽  
Electron Microscopic ◽  
Morphological Studies ◽  
Electron Microscopic Technique ◽  
Scanning Electron Microscopic ◽  
Thermal Stability Of

In this work pure polyindole and its composites with wollastonite have been prepared by using anhydrous ferric chloride (FeCl3) as an oxidizing agent. Wollastonite (CaSiO3) was prepared by sol gel method using citric acid, calcium nitrate and tetraethylorthosilicate (TEOS) for the synthesis of composites. Particle size of the synthesized wollastonite was 58.8 nm. Effect of wollastonite weight percentages ranging from 1-25% of the polyindole in polyindole wollastonite (PIn/CaSiO3) composites was studied. Chemical structure was elucidated for polyindole/wollastonite (PIn/CaSiO3) composites and wollastonite (CaSiO3) was done through Fourier transform infra red spectroscopy (FTIR), which revealed successful fabrication of polyindole/wollastonite (PIn/CaSiO3) composites and wollastonite (CaSiO3) particles. Scanning electron microscopic technique was used for surface morphological studies. Thermal stability of the composites was examined through thermogravimetry. Four probe method was used to measure DC-conductivity of the samples. Composites showed DC conductivity in the range, 3.71´10-7 Siemens per centimeter.

Sol-gel synthesis and the effect of boron addition on the phosphorescent properties of SrAl2O4:Eu2+,Dy3+ phosphors

2001 ◽  
Vol 16 (3) ◽  
pp. 644-651 ◽  
Author(s):  
I-Cherng Chen ◽  
Teng-Ming Chen
Keyword(s):  
Luminescence Intensity ◽  
Sol Gel ◽  
Time Dependent ◽  
Boron Addition ◽  
Electron Microscopic ◽  
Morphological Studies ◽  
Bluish Green ◽  
Scanning Electron Microscopic ◽  
Sol Gel Synthesis ◽  
Scanning Electron

The effects of boron addition on the microstructure and afterglow properties of the long-phosphorescent SrAl2O4:Eu2+,Dy3+ (SAED), synthesized via a novel sol-gel route, were systematically investigated. Significant improvement on luminescence intensity and the lengthening of afterglow persistent time in boron-added SAED (BSAED) phases were observed, as compared to those without boron addition and commercial phosphors. Typical bluish-green emissions attributed to the doublet phosphorescence with wavelengths peaking at 412 and 501 nm for BSAED phase and 398 and 486 nm for the pristine SAED phase were observed. Afterglow with wavelengths peaking at 403 and 485 nm was observed for BSAED phase, whereas that with wavelengths peaking at 486.5 nm was found for the pristine SAED phase, as indicated by time-dependent afterglow decay profiles. Results from scanning electron microscopic morphological studies were used to investigate the modification of microstructure of the BSAED phases.

Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

2012 ◽  
Vol 727-728 ◽  
pp. 1552-1556
Author(s):  
Renata Barbosa ◽  
Dayanne Diniz Souza ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Chemical Structure ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Degradation Mechanisms ◽  
Scanning Calorimetry ◽  
Higher Temperature ◽  
Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

Structural and Optical Characterization of Synthesized TiO2 Nanopowder Using Sol–Gel Technique

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650002 ◽  
Author(s):  
S. Lourduraj ◽  
R. Victor Williams
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Visible Spectrum ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Morphological Studies ◽  
Atomic Force ◽  
Gel Technique

The nanocrystalline TiO2 powder was synthesized by sol–gel method. The XRD analysis reveals that TiO2 powder was highly crystalline (anatase phase) and nanostructured with tetragonal system. The average crystallite size after calcined at 673[Formula: see text]K is found to be 7.7[Formula: see text]nm. The surface morphological studies using scanning electron microscopy (SEM) exhibit that the formation of nanosized TiO2 particles with less densification nature. Atomic force microscopy (AFM) topography exhibits the uniform distribution of spherical-shaped particles. The energy dispersive X-ray spectroscopy (EDX) confirms the presence of Titanium and Oxygen in synthesized TiO2 nanopowder. The value of optical bandgap of TiO2 nanopowder calculated from UV-Visible spectrum is 3.45[Formula: see text]eV. The presence of TiO2 particles is confirmed from the dominant fourier transform infrared (FTIR) peaks at 621[Formula: see text]cm[Formula: see text] and 412[Formula: see text]cm[Formula: see text].

scholarly journals Preparation and Properties of Thermoplastic Starch/Bentonite Nanocomposites

2017 ◽  
Vol 885 ◽  
pp. 129-134 ◽  
Author(s):  
László Lendvai ◽  
Ákos Kmetty ◽  
József Karger-Kocsis
Keyword(s):  
Thermoplastic Starch ◽  
Test Results ◽  
Maize Starch ◽  
Screw Extruder ◽  
Electron Microscopic ◽  
Sem Images ◽  
Scanning Electron Microscopic ◽  
Twin Screw ◽  
Thermal Stability Of ◽  
Scanning Electron

Thermoplastic starch (TPS)/bentonite nanocomposites containing up to 7.5 wt.% bentonite were prepared. Maize starch was plasticized with glycerol and water, in presence or absence of bentonite, in a twin-screw extruder. Mechanical, morphological and thermal properties of the TPS/bentonite nanocomposites were determined and discussed. Scanning electron microscopic (SEM) images revealed a good dispersion of bentonite particles with some remaining agglomerates in the range of 0.1 to 1.5 μm. According to the tensile test results the tensile strength and Young’s modulus increased significantly with increasing bentonite content, however, at cost of elongation. Thermogravimetric analysis (TGA) showed that the presence of bentonite exerted little to no effect on the thermal stability of TPS.

scholarly journals Biferrocenyl Schiff bases as efficient corrosion inhibitors for an aluminium alloy in HCl solution: a combined experimental and theoretical study

RSC Advances ◽  
2020 ◽  
Vol 10 (13) ◽  
pp. 7585-7599 ◽  
Author(s):  
Uzma Nazir ◽  
Zareen Akhter ◽  
Naveed Kausar Janjua ◽  
Muhammad Adeel Asghar ◽  
Sehrish Kanwal ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Theoretical Study ◽  
Electrochemical Impedance ◽  
Electron Microscopic ◽  
Loss Analysis ◽  
Tafel Polarization ◽  
Electron Microscopic Technique ◽  
Scanning Electron Microscopic ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The anticorrosion activity of biferrocenyl Schiff bases on AA2219-T6 in acidic medium were studied using Tafel polarization, electrochemical impedance spectroscopy, weight loss analysis, FT-IR spectroscopy and scanning electron microscopic technique.

Tribocorrosion behavior of electroless Ni-P/Ni-B duplex coating on AA7075 aluminum alloy

2019 ◽  
Vol 71 (5) ◽  
pp. 630-635 ◽  
Author(s):  
Harun Mindivan
Keyword(s):  
Aluminum Alloy ◽  
Surface Characterization ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Content Type ◽  
Duplex Coating ◽  
Scanning Electron Microscopic ◽  
Electroless Ni ◽  
Insight Into

Purpose This paper aims to investigate the structural, corrosion and the study of tribocorrosion features of the AA7075 aluminum alloy with and without the application of electroless Ni-P/Ni-B duplex coating with a thickness of approximately 40 microns. Design/methodology/approach Surface characterization of the samples was made by structural surveys (light optic microscope, scanning electron microscopic examinations and X-ray diffraction analyses), hardness measurements, corrosion and tribocorrosion tests. Findings Results of the experiments showed that upper Ni-B coating deposited on the surface of first Ni-P layer by duplex treatment caused remarkable increment in the hardness, corrosion resistance and tribocorrosion performance as compared to the AA7075 aluminum alloy. Originality/value This study can be a practical reference and offers insight into the effects of duplex treating on the increase of hardness, corrosion and tribocorrosion performance.

Synthesis and characterization of diaminomaleonitrile-functionalized polystyrene grafts for application in pervaporation separation

2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Hamada Abdel-Razik
Keyword(s):  
Chemical Structure ◽  
Thermal Characteristics ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Optimum Conditions ◽  
Scanning Calorimetry ◽  
Phenol Water ◽  
Pervaporation Separation ◽  
Thermal Stability Of

AbstractSynthesis, characterization and application of diaminomaleonitrile (DAMN)-functionalized polystyrene grafts were studied. Dibenzoyle peroxide (BP) was used as an initiator. Optimum conditions for grafting were found to be c(DAMN) = 0.5 M, c(BP) = 0.016 M, θ = 85 °C and t = 4 h. Water uptake of the polystyrene graft membranes was found to increase with the increase of the grafting yield. The chemical structure, thermal characteristics and thermal stability of the obtained membranes were investigated by means of FTIR spectroscopy, differential scanning calorimetry, and thermal gravimetric analysis. Polystyrene graft membrane with the degree of grafting of up to 96 % was found to be useful for the pervaporation separation of phenol/water mixtures.

Preparation and Characterization of Blended Composite Membranes

2012 ◽  
Vol 488-489 ◽  
pp. 506-510 ◽  
Author(s):  
Sikander Rafiq ◽  
Zakaria Man ◽  
Abdulhalim Maulud ◽  
Nawshad Muhammad ◽  
Saikat Maitra
Keyword(s):  
Spectroscopic Analysis ◽  
Sol Gel ◽  
Composite Membranes ◽  
Hybrid Membranes ◽  
Ftir Analysis ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Thermal Stability Of ◽  
Scanning Electron

Composite membranes were prepared by incorporating inorganic silica nanoparticles into blends of polysulfone/polyimide (PSF/PI) membranes via sol-gel route. Morphological structures of the developed membranes were carried out by scanning electron microscopy (SEM). Spectroscopic analysis of the hybrid membranes were done by fourier transform infrared spectroscopy (FTIR) analysis. Differential scanning calorimetry (DSC) analysis shows that the glass transition temperature (Tg) increased from 209oC to 238oC in the hybrid membranes followed by thermogravimetric analysis (TGA) that showed significant improvement in thermal stability of the developed membranes.

Synthesis and Characterization of Li(Li0.05Ni0.6Fe0.1Mn0.25)O2 Cathode Material for Lithim Ion Batteries

2018 ◽  
Vol 21 (1) ◽  
pp. 051-056
Author(s):  
A. Nichelson ◽  
S. Thanikaikarasan ◽  
K. Karuppasamy ◽  
S. Karthickprabhu ◽  
T. Mahalingam ◽  
...  
Keyword(s):  
Cathode Material ◽  
Sol Gel ◽  
Lithium Ion ◽  
Chelating Agent ◽  
X Ray Diffraction ◽  
Morphological Studies ◽  
New Type ◽  
Ft Ir ◽  
Ir And Raman

A new type of lithium enriched cathode material Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 was synthesized by sol-gel method with citric acid as a chelating agent. The structural and morphological studies were systematically investigated through X-ray diffraction, SEM with EDS, FT-IR and Raman analyses. The crystallite size of the Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 cathode material was found to be 45 nm thereby leads to the feasible movement of lithium ion all through the material. FT-IR spectroscopy was used to confirm the metal-oxygen interaction in the prepared cathode material. The electrical properties of the Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 cathode material were studied by impedance and dielectric spectral analyzes. Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 showed a maximum ionic conductivity of 10-6 S/cm at ambient temperature.

Ancient Marble Sculpture: Geochemical Characterization of Surficial Weathering Products

1988 ◽  
Vol 123 ◽  
Author(s):  
Stanley V. Margolis ◽  
Frank Preusser ◽  
W.J. Showers
Keyword(s):  
Rock Weathering ◽  
Important Goal ◽  
Ancient Greek ◽  
Carbon And Oxygen Isotopes ◽  
Electron Microscopic ◽  
Geochemical Characterization ◽  
Carbon Isotopic ◽  
Scanning Electron Microscopic

AbstractQuantitative scientific determination of the authenticity and age of marble sculpture is an important goal of geo-archaeologists and conservation scientists. Geochemical and petrographic techniques are used here to investigate rock weathering and mineral alterations responsible for the “patina” and alteration layers on marble sculpture. We present oxygen and carbon isotopic, scanning electron microscopic and electron microprobe analyses of both fresh marble and weathering crusts materials from cores taken from Cycladic and Archaic Greek sculptures and from ancient quarries, to evaluate these techniques as indicators of antiquity.Calcitic marbles exhibit an altered weathering crust of variable thickness, where calcite has been recrystallized and interpenetrated with inclusions of iron oxide, clay minerals, gypsum and other authigenic minerals. The thickness and composition of these crusts varies with soil and water chemistry as well as marble density, texture and age.Microprobe analyses indicate trace element gradients from fresh to weathered calcite. Carbon and oxygen isotopes can differentiate between insitu alteration and precipitated carbonate. Dolomitic marbles can exhibit calcitic surficial layers formed by dedolomitization, which can be confirmed by isotopic and microprobe analyses.Analyses of known forgeries, ancient quarry samples and artificially weathered marbles have further documented our criteria and show that the majority of diagnostic geochemical and mineralogical features seen on ancient Greek sculptures cannot be accurately duplicated by artificial means.

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