Effects of Preparation Approaches and Oxidizing agents on the Yield, Morphology and Thermal stability of Polyaniline

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Wan Ahmad Kamil Mahmood ◽  
Mohammad Mizanur Rahman Khan ◽  
Yeap Guan Yeow ◽  
Yee Keat Wee
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Reaction Time ◽  
Secondary Growth ◽  
Rapid Mixing ◽  
Oxidizing Agents ◽  
Mechanical Stirring ◽  
Transmission Electron ◽  
Ft Ir ◽  
Polymerization Method

Abstract Evidence of the control of yield and different morphological features of polyaniline (PANI), along with their higher thermal stability is reported. The syntheses were performed by varying the reaction time from 2 to 6 hours for three different methods using three different oxidizing agents. The freshly prepared PANI was investigated by means of fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-Vis), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The polymer yield was increased with the increasing of reaction time from 2 to 6 h for all oxidants in the synthesis approaches; while the reverse trend was observed for KPS in rapid mixing polymerization and mechanical stirring methods. The highest yield was obtained for 6 h reaction time using APS through mechanical stirring method. FESEM analysis showed the growth of regular and uniform PANI nanoparticles, along with the prevention of secondary growth and agglomeration of primary nanofibers using all three oxidizing agents for sonochemistry and rapid mixing polymerization method, except H2O2 in the case of later technique. However, irregular and agglomerated PANI was found for all oxidants in mechanical stirring method. TGA data showed that PANI synthesized by mechanical stirring method is thermally more stable than those prepared by sonochemistry and rapid mixing polymerization.

Ultrasound promoted green oxidation of alkenes with hydrogen peroxide in the presence of iron porphyrins supported on multi-walled carbon nanotubes

2015 ◽  
Vol 19 (04) ◽  
pp. 622-630 ◽  
Author(s):  
Saeed Rayati ◽  
Zahra Sheybanifard
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Hydrogen Peroxide ◽  
Heterogeneous Catalyst ◽  
Multi Wall Carbon Nanotubes ◽  
Mechanical Stirring ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes

In the present work, oxidation of alkenes with hydrogen peroxide in the presence of meso-tetrakis(4-hydroxyphenyl)porphyrinatoiron(III) chloride supported onto surface of functionalized multi-wall carbon nanotubes (FMWCNT), [ Fe ( THPP ) Cl@MWCNT ], is reported. The simple heterogeneous catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and also thermal analysis. The amount of the catalyst loaded on the nanotubes was determined by atomic absorption spectroscopy. This heterogeneous catalyst proved to be an efficient and green catalyst and was successfully able to activate hydrogen peroxide without any additive toward the oxidation of alkenes in ethanol as a green solvent. Performance of the catalyst in oxidation of various alkenes was inspected under reflux, ultrasonic irradiation and mechanical stirring. Moreover, the catalyst can be reused several times under similar conditions.

A Comparative Study of Metal Oxides (CaO, CuO and CaO/CuO) Effects on the Morphology and Thermal Stability of PANI Nanofibers

2015 ◽  
Vol 819 ◽  
pp. 262-267
Author(s):  
Mohammad Mizanur Rahman Khan ◽  
Wan Ahmad Kamil Mahmood ◽  
Yee Keat Wee ◽  
Hanis binti Azizan
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Surface Morphology ◽  
Secondary Growth ◽  
Visible Spectroscopy ◽  
Pani Nanofibers ◽  
Combined Use ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Scanning Electron

The comparison of the influence of CaO and CuO alone and combined CaO/CuO on the diameter, surface morphology and thermal stability of polyaniline (PANI) nanofibers is reported. The possible incorporation of CaO and CuO in PANI was revealed by both fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectroscopy (UV–vis). It was found that the diameter of PANI nanofibers varied for the addition of CaO and CuO alone compared to their combined use. Field emission scanning electron microscopy (FESEM) showed that the addition of CaO, CuO and CaO/CuO consistently produce composite material in nanofibers structures. This nanofibers shows regular and uniform surface morphology and without secondary growth and agglomeration of the primary nanofibers. Thermogravimetric analysis (TGA) data showed better thermal stability for all composite materials as compared to PANI nanofibers.

Preparation and Thermal Stability of Micro/Nano Silicone Rubber Particles

2011 ◽  
Vol 399-401 ◽  
pp. 718-721
Author(s):  
Fei Wang ◽  
Xin Long Wang
Keyword(s):  
Thermal Stability ◽  
Silicone Rubber ◽  
Crosslinking Agent ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ft Ir ◽  
And Performance ◽  
Polymerization Method ◽  
Thermal Stability Of

The micro/nano particles of silicone rubber were prepared with α, ω-dihydroxy polyorganosiloxane, as basic polymer and crosslinking agent via emulsion polymerization method at room temperature. The structure and performance of the particles were characterized by transmission electron microscopy (TEM), FT-IR, thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results indicated that the particles had certain ordered structure and thermal stability.

Synthesis and Characterization of Surface Modification of TiO2 Nanoparticles for Electrophoretic Display

2011 ◽  
Vol 361-363 ◽  
pp. 1960-1964 ◽  
Author(s):  
Yu Bai ◽  
Shu Xian Meng ◽  
Ya Qing Feng
Keyword(s):  
Electron Microscopy ◽  
Control Agent ◽  
Dielectric Medium ◽  
Transmission Electron ◽  
Ft Ir ◽  
A Charge ◽  
Electronic Ink ◽  
Polymerization Method ◽  
Display Technique

TiO2 and carbon black inorganic pigments having opposite charges have been typically used for white and black image in the electronic ink display technique, respectively. However, since TiO2has a relatively high density, the density mismatch between nanoparticles and the dielectric medium causes severe sedimentation problem in the suspended media. In order to change its surface from hydrophilic to hydrophobic and lower its density, TiO2was grafted by γ-Methacryloxypropyl trimethoxy silane (KH570), and then coated with poly(methyl methacrylate) (PMMA) via a dispersion polymerization method prior to being used for an electronic ink material. In order to improve their mobility, a charge control agent was also added to the suspension of synthesized nanoparticles in the dielectric medium. The KH570-grafted TiO2nanoparticles and the TiO2/KH570/PMMA nanoparticles were characterized by fourier transform-infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Density of TiO2/KH570/PMMA nanoparticles was found to be decreased. Thermal properties of the composite particles were analyzed by thermogravimetric analysis (TGA).

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

scholarly journals Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Photocatalytic Reactions ◽  
Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

Effect of hydrothermal dwell time on the diameter-controlled synthesis and magnetic property of MnO2 nanorods

2014 ◽  
Vol 28 (06) ◽  
pp. 1450045 ◽  
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-Ain Javed ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Dwell Time ◽  
Hydrothermal Reaction ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Hydrothermal Reaction Time

In this paper, single crystalline 1D tetragonal MnO 2 pen-type nanorods were synthesized by varying the dwell time through a facile hydrothermal route at a reaction temperature of 250°C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the diameter of MnO 2 nanorods decreases from 460 nm to 250 nm with the increase in hydrothermal reaction time from 5 h to 15 h. Field-emission scanning electron microscopy (FESEM) and TEM studies revealed the evolution of improved surface morphology of MnO 2 nanorods that are prepared with longer hydrothermal reaction time. The magnetic properties of the products were evaluated using vibrating sample magnetometer (VSM) at room temperature, which showed that the as-prepared samples exhibit weak ferromagnetic behavior. The effect of diameter on the magnetization values was observed and discussed in detail.

Effect of Synthesis Temperature on Particles Size and Morphology of Zirconium Oxide Nanoparticle

2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Zirconium Oxide ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
Ft Ir

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.

Eu3+/Tb3+ Co-Doped Cerium Oxide Transparent Nanocomposite for Color-Tunable Emission

NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850119
Author(s):  
Xiaoyan Li ◽  
Yunlong Yu ◽  
Xiangfeng Guan ◽  
Peihui Luo ◽  
Linqin Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Sol Gel ◽  
Homogeneous Precipitation ◽  
Transmission Electron ◽  
Color Tunable ◽  
Co Doped ◽  
Tunable Emission

Eu[Formula: see text]/Tb[Formula: see text] co-doped nanocomposite containing CeO2 nanocrystals was successfully prepared by an in situ sol–gel polymerization approach. High-resolution transmission electron microscopy demonstrated the homogeneous precipitation of CeO2 nanocrystals among the polymethylmethacrylate (PMMA) matrix. The thermal stability and UV-shielding capability of the obtained nanocomposite were improved with increase of CeO2 content. The tuning of the emissive color from green and yellow to red can be easily achieved by varying the dopant species and concentration. These results suggested that the obtained nanocomposite could be potentially applicable in transparent solid-state luminescent devices.

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