scholarly journals Structural and Thermal Studies of ZnS and CdS Nanoparticles in Polymer Matrices

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Jejenija Osuntokun ◽  
Peter A. Ajibade
Keyword(s):  
Polymer Nanocomposites ◽  
Thermal Studies ◽  
Electronic Spectroscopy ◽  
Metal Sulfides ◽  
Poly Vinyl Alcohol ◽  
Cds Nanoparticles ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Crystallite Sizes

We report the synthesis and structural studies of ZnS and CdS nanoparticles in polyvinylpyrrolidone (PVP), poly(vinyl alcohol) (PVA), and poly(methyl methacrylate) (PMMA) matrices. The metal sulfides/polymer nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, electronic spectroscopy (UV-Vis), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The particle sizes as calculated from the absorption spectra were in agreement with the results obtained from TEM and XRD data. They showed metal sulfides nanoparticles in the polymers matrices with average crystallite sizes of 1.5–6.9 nm. The TGA results indicate that incorporation of the nanoparticles significantly altered the thermal properties of the respective polymers with ZnS/PVA and CdS/PVA nanocomposites displaying higher thermal stability than the other polymer nanocomposites.

scholarly journals Synthesis and Characterization of Metal Sulfides Nanoparticles/Poly(methyl methacrylate) Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Peter A. Ajibade ◽  
Johannes Z. Mbese
Keyword(s):  
Electron Microscope ◽  
Methyl Methacrylate ◽  
Metal Sulfides ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Poly Methyl Methacrylate ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
20 Nm

Metal sulfides nanoparticles in poly(methyl methacrylate) matrices were prepared and characterized by infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). The FTIR confirms the dispersion of the nanoparticles in PMMA matrices with the C=O and C–O–C bonds of the PMMA shifting slightly which may be attributed to the interactions between the nanoparticles and PMMA. The ZnS nanoparticles in PMMA have average crystallite sizes of 4–7 nm while the CdS has particle size of 10 nm and HgS has crystallite sizes of 8–20 nm. The increasing order of particle sizes as calculated from the XRD is ZnS/PMMA<HgS/PMMA<CdS/PMMA and ranges from 1.02 to 1.35 nm. These calculated particle sizes are smaller than the values obtained from TEM.

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.

Nickel Nanoparticles Supported on Diphenylphosphinated Poly(Vinyl Alcohol-Co-ethylene) as a New Heterogeneous and Recyclable Catalyst for Mizoroki–Heck Reactions

2017 ◽  
Vol 41 (9) ◽  
pp. 541-546 ◽  
Author(s):  
Farzaneh Ebrahimzadeh
Keyword(s):  
Vinyl Alcohol ◽  
Nickel Nanoparticles ◽  
Supported Catalysts ◽  
Low Cost ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Heck Reactions ◽  
Modified Polymer ◽  
Transmission Electron ◽  
High Metal

Nickel nanoparticles (NiNPs) supported on diphenylphosphinated poly(vinyl alcohol- co-ethylene) (DPP-PVA- co-PE) were synthesised by first reacting poly(vinyl alcohol- co-ethylene) with chlorodiphenylphosphine (ClPPh2) under basic conditions and then treating the product with Ni(OAc)2 followed by reduction with NaBH4. (DPP-PVA- co-PE)-NiNPs, a new metallised polymer, was then shown to efficiently catalyse Mizoroki–Heck reactions of aryl iodides, bromides or activated chlorides with olefins such as styrene and n-butyl acrylate in dimethylformamide. In contrast with other polymer-supported catalysts, the main advantage of this method is the low cost of the catalyst due to the simple synthetic route using easily obtained materials and good recoverability. Transmission electron microscopy and X-ray diffraction measurements were used to show the high metal dispersion and small sizes of Ni nanoparticle on the surface of the modified polymer. DPP-PVA- co-PE-NiNPs could be recycled several times.

scholarly journals The Evaluation of Meloxicam Nanocrystals by Oral Administration with Different Particle Sizes

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 421
Author(s):  
Yao Yu ◽  
Yang Tian ◽  
Hui Zhang ◽  
Qingxian Jia ◽  
Xuejun Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Water Solubility ◽  
Cell Model ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laser Scattering ◽  
Transport Studies ◽  
Transmission Electron ◽  
Transmission And Absorption

Meloxicam (MLX) is a non-steroidal anti-inflammatory drug used to treat rheumatoid arthritis and osteoarthritis. However, its poor water solubility limits the dissolution process and influences absorption. In order to solve this problem and improve its bioavailability, we prepared it in nanocrystals with three different particle sizes to improve solubility and compare the differences between various particle sizes. The nanocrystal particle sizes were studied through dynamic light scattering (DLS) and laser scattering (LS). Transmission electron microscopy (TEM) was used to characterize the morphology of nanocrystals. The sizes of meloxicam-nanocrystals-A (MLX-NCs-A), meloxicam-nanocrystals-B (MLX-NCs-B), and meloxicam-nanocrystals-C (MLX-NCs-C) were 3.262 ± 0.016 μm, 460.2 ± 9.5 nm, and 204.9 ± 2.8 nm, respectively. Molecular simulation was used to explore the distribution and interaction energy of MLX molecules and stabilizer molecules in water. The results of differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) proved that the crystalline state did not change in the preparation process. Transport studies of the Caco-2 cell model indicated that the cumulative degree of transport would increase as the particle size decreased. Additionally, plasma concentration–time curves showed that the AUC0–∞ of MLX-NCs-C were 3.58- and 2.92-fold greater than those of MLX-NCs-A and MLX-NCs-B, respectively. These results indicate that preparing MLX in nanocrystals can effectively improve the bioavailability, and the particle size of nanocrystals is an important factor in transmission and absorption.

Evaluation of Surfactants on Thermo-Physical Properties of Magnesia-Oil Nanofluid

2018 ◽  
Vol 928 ◽  
pp. 106-112 ◽  
Author(s):  
Abdallah Yousef Mohammed Ali ◽  
Ahmed H. El-Shazly ◽  
M.F. Elkady ◽  
S.E. AbdElhafez
Keyword(s):  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Mgo Nanoparticles ◽  
Transmission Electron ◽  
Wet Chemical ◽  
Cetyl Trimethyl Ammonium ◽  
Poly Vinyl Pyrrolidone ◽  
The Impact

The prime purpose of the current study was to investigate the consequence of surfactant on the kinematic viscosity, thermal conductivity, and stability of MgO-oil based nanofluid. Magnesia (MgO) nanoparticles were prepared by the wet chemical method. Structural and morphological analysis of synthesized nanoparticles were performed via X-ray diffraction (XRD) and Transmission electron microscope (TEM). Subsequently, nanofluid was prepared at a solid concentration of 0.025% in presence of various surfactants with the aid of ultrasonic technique. The impact of the different surfactants (Cetyl Trimethyl Ammonium Bromide (CTAB), Poly Vinyl Pyrrolidone (PVP), Poly Vinyl Alcohol (PVA), and Oleic Acid) on the nanofluid stability was tested. It was evident that CTAB and PVA surfactants establish the most stable prepared MgO-oil based nanofluid. The experiments revealed that the maximum UV–Vis absorbance of the solution corresponds to the dispersion of CTAB in the base fluid.

Particle Size Analysis of the Synthesized Al2O3 by Dissolution and Alkali Fusion-Coprecipitation Methods

2020 ◽  
Vol 860 ◽  
pp. 128-134
Author(s):  
Cahyaning Fajar Kresna Murti ◽  
Malik Anjelh Baqiya ◽  
Endarko ◽  
Triwikantoro
Keyword(s):  
Particle Size ◽  
Ammonium Hydroxide ◽  
Particle Size Analysis ◽  
Fusion Product ◽  
Size Analysis ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Bottom Up ◽  
Alkali Fusion ◽  
Transmission Electron

Particle size analysis of synthesized Al2O3 by dissolution and alkali fusion-coprecipitation methods has been conducted. The formation of nano- or microparticles can be synthesized by the top-down (physically) and bottom-up (chemically) methods. In this study, the commercial alumina (Merck) with the particle size of 63 µm was synthesized through the bottom-up method. The dissolution method was done by reacting to alumina with ammonium hydroxide (NH4OH). The alkali fusion method was carried out by reacting alumina with sodium hydroxide (NaOH) and it obtained by coprecipitation of the alkali fusion product with HCl and NH4OH. The result from both methods were calcined at 600°C. The phase of synthesized Al2O3 was identified by using X-ray diffraction (XRD), whereas the morphology observed using a transmission electron microscope (TEM), and the particle sizes measured by particle sizes analyzer (PSA). The XRD pattern shows the γ-Al2O3 phases with particle sizes of ~33 nm and ~25 nm from TEM observations, while the PSA results revealed agglomerated particles with particle sizes of 1263 nm and 477 nm for the dissolution and alkali fusion-coprecipitation method, respectively. Therefore, both methods can be used to reduce the particle size of γ-Al2O3.

Solvothermal/ Hydrothermal Synthesis of Metal Oxides and Metal Powders with and without Microwaves

2010 ◽  
Vol 65 (8) ◽  
pp. 1033-1037 ◽  
Author(s):  
Sridhar Komarneni ◽  
Young Dong Noh ◽  
Joo Young Kim ◽  
Seok Han Kim ◽  
Hiroaki Katsuki
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Reducing Agents ◽  
Particle Sizes ◽  
Metal Powders ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Very Low Temperature

Anatase and Ca, Sr and Ca0.5Sr0.5 hydroxyapatites were synthesized by conventional-hydrothermal (C-H) as well asmicrowave-hydrothermal (M-H)methods.Microwave-assisted reactions led to accelerated syntheses of anatase but no such acceleration of reactions could be detected with the syntheses of hydroxyapatites because the crystallization of the latter materials occurred at very low temperature. Cu and Au metal powders were produced by using glucose, fructose or sucrose as reducing agents under C-H conditions at 160 ℃, where fructose and sucrose were found to be stronger reducing agents than glucose. The crystallinity of all the powders was characterized by powder X-ray diffraction, and morphology and particle sizes were determined by scanning or transmission electron microscopy

Low Temperature Synthesis and Characterization of CaO and MgO- Stabilized Nanocrystalline Tetragonal Zirconia by Citrate Gel Process

2008 ◽  
Vol 368-372 ◽  
pp. 754-757
Author(s):  
Hasan Gocmez ◽  
Hirotaka Fujimori
Keyword(s):  
Single Phase ◽  
Tetragonal Zirconia ◽  
Xrd Analysis ◽  
Complex Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Heat Treated ◽  
Crystallite Sizes ◽  
Citrate Gel Process

The citrate gel method, similar to the polymerized complex method, was used to synthesize homogenous tetragonal zirconia at 800oC and 1000oC. Nanocrystalline tetragonal single phase has been fully stabilized with 3, 7, 10 mol% CaO and 10, 15 mol% MgO at 800oC, respectively. In addition, the XRD analysis showed the absence of monoclinic phase after addition of 7 and 10 mol% CaO into zirconia-based solid solutions, which have been fully stabilized both 800oC and 1000oC. The crystallite sizes of the t-ZrO2 with 3, 7 and 10 mol% CaO at 1000oC were 32, 28 and 29nm, respectively. For ZrO2- x mol% MgO (x=3, 10, 15) solid solution, the crystallite sizes of samples at 800oC were less than 29nm, however it was increased up to 69nm at 1000oC. The prepared gel and subsequent heat-treated powders were characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM) to get detail information regarding to differentiation of polymorphs of zirconia as well as formation of powders.

scholarly journals Effects of Size and Dispersity of Microcrystalline Celluloses on Size, Structure and Stability of Nanocrystalline Celluloses Extracted by Acid Hydrolysis

Nano LIFE ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1441014 ◽  
Author(s):  
Qi Liu ◽  
Weiping Hao ◽  
Yongguang Yang ◽  
Aurore Richel ◽  
Canbin Ouyang ◽  
...  
Keyword(s):  
Particle Size ◽  
Acid Hydrolysis ◽  
Size Structure ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Sonication Treatment

Nanocrystalline celluloses (NCCs) were separated from four commercial microcrystalline celluloses (MCCs) by an acid hydrolysis–sonication treatment. Transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectrum, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were conducted to investigate the NCCs. MCCs with different morphologies and particle sizes showed different aggregation degrees. The aggregation of MCCs followed the order MCC1 > MCC3 > MCC2 > MCC4, which is the same order of the heights of the resulting NCCs. The best uniformity and thermal stability were characterized for NCC3, which was produced by MCC3 with smallest original particle size and good dispersity among the four MCCs. This result suggests that both the original particle size and dispersity of MCCs had significant effects on separated NCCs.

Microstructural characteristics and photoluminescence performance of nanograined thermally treated CeO2-TiO2 xerogels

2007 ◽  
Vol 22 (5) ◽  
pp. 1182-1187
Author(s):  
Amita Verma ◽  
A.K. Srivastava ◽  
N. Karar ◽  
Harish Chander ◽  
S.A. Agnihotry
Keyword(s):  
Electron Microscopy ◽  
Crystallite Size ◽  
Sol Gel ◽  
Structural Features ◽  
X Ray Diffraction ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Crystallite Sizes ◽  
Thermally Treated

Nanostructured thermally treated xerogels have been synthesized using a sol-gel process involving cerium (Ce) chloride heptahydrate and titanium (Ti) propoxide mixed in different Ce:Ti molar ratios. Structural features of the xerogels have been correlated with their photoluminescence (PL) response. The crystallite sizes in the samples lie in the nanorange. The x-ray diffraction and transmission electron microscopy results have confirmed the coexistence of CeO2 and TiO2 nanocrystallites in these xerogels. In general, a decrease in the CeO2 crystallite size and an increase in the TiO2 crystallite size are observed in the xerogels as a function of Ti content. Scanning electron microscopy results have evidenced the evolution of ordered structure in the xerogels as a function of TiO2 content. Although both of the phases (CeO2 and TiO2) have exhibited PL in ultraviolet and visible regions, the major luminescence contribution has been made by the CeO2 phase. The largest sized CeO2 crystallites in 1:1 thermally treated xerogel have led to its highest PL response. PL emission in the xerogels is assigned to their nanocrystalline nature and oxygen vacancy-related defects.

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