scholarly journals Irradiation of a Nanocomposite of Pseudoboehmite-Nylon 6,12

2010 ◽  
Vol 71 ◽  
pp. 28-33 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Renato Meneghetti Peres ◽  
L.H. Silveira ◽  
Leonardo Gondim Andrade e Silva ◽  
L.F. de Miranda

Nanocomposites are nanometrical material particles embedded in a specific matrix. The degree of organization of the nanostructures and their properties depend on the nature of the organic and inorganic components of the structure that can generate synergic interactions. Polymeric nanocomposites are related to a class of hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. In the present work, nanocomposites of nylon 6,12 with different concentrations of pseudoboehmite obtained by sol-gel process were prepared with and without the presence of octadecylamine. After preparation, the samples were irradiated with a 200 kGy radiation dose in an electron accelerator. The pseudoboehmite nano particles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite promoted a reduction of the melting flow during the production of the composites evidencing the interaction of pseudoboehmite with the polymeric matrix, probably modifying its crystalline structure.

2014 ◽  
Vol 798-799 ◽  
pp. 732-736
Author(s):  
Renato Meneghetti Peres ◽  
C.Y.U. Peres ◽  
Leila F. de Miranda ◽  
Cesar Denuzzo ◽  
Gabriel Cavalcante Gomes ◽  
...  

Polymers nanocomposites are composed by nanometrical particles embedded in a specific matrix. Additions of small amount of nanoparticles of inorganic material in specific matrixes can greatly improve mechanical properties. The high specific surface area of the inorganic materials nanoparticles promotes its dispersion in the polymeric matrix, and the obtained properties are strongly related to the homogeneity of the dispersion. In the present work, nylon 6.12 nanocomposites with different concentrations of pseudoboehmite obtained by sol-gel process were prepared with different concentrations of octadecylamine. The pseudoboehmite was characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite reduces the melting flow, evidencing the interaction of pseudoboehmite with the polymeric matrix probably modifying its crystalline structure.


2006 ◽  
Vol 45 ◽  
pp. 260-265 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Leila Figueiredo de Miranda ◽  
G.N. Uehara

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate as precursor. It was used a 2n full factorial design for studying the effect of the temperature of synthesis, the concentration of ammonium hydroxide, and the radiation dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by scanning electron microscopy, x-ray diffraction of the product (after firing the pseudoboehmite at different temperatures), and it was also analyzed the temperature of endothermic and exothermic transformations using the thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that α-alumina was obtained at 1100o C.


2017 ◽  
Vol 47 ◽  
pp. 96-105 ◽  
Author(s):  
Leila Figueiredo de Miranda ◽  
Leid Jeane Pastrolin Goulart ◽  
Leonardo G. de Andrade e Silva ◽  
Alexandre Crioruska Donadon ◽  
Fabio Yuji Yamasaki ◽  
...  

Polymeric nanocomposites are hybrid materials in which inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. These inorganic substances have high surface area allowing a better interaction with the polymeric matrix and consequently promote changes in the physical properties of the final composite with small additions of the same. The preparation of nanocomposites with polymer matrix allows in many cases to find a relationship between a low cost due to the use of lower amount of charge, reaching high level of performance. In this work, it was obtained polystyrene nanocomposites with pseudoboehmite synthesized by the sol-gel process with different concentrations of pseudoboehmite using and not using octadecylamine as a coupling agent. The nanocomposites were prepared by the melt intercalation technique. The pseudoboehmite nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by differential thermal analysis, thermogravimetric analysis, heat deflection temperature, Vicat softening point, mechanical and rheological tests. The results showed an increase in the thermal properties, hardness and tensile strength values and decrease in the melt index, impact resistance and tensile elongation, showing the interaction of the filler with the polymer matrix. Although in the samples with the presence of octadecylamine the data shows that the thermomechanical properties practically do not vary in relation with the samples without octadecylamine.


2019 ◽  
Vol 70 (6) ◽  
pp. 2044-2047
Author(s):  
Alexandru-Horatiu Marincas ◽  
Firuta Goga ◽  
Roxana Dudric ◽  
Crina Suciu ◽  
Alexandra Avram ◽  
...  

In the present paper, nanosized La0.9Sr0.1MnO3 particles were synthesized via a facile modified sol-gel route using two cheap and environmentally friendly organic chemicals, namely sucrose and pectin. The obtained powders were characterized by thermo gravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and magnetic measurements. The optimal temperature for obtaining nanosized particles was determined as 1000�C and 1h dwell time was enough to obtain crystalline nanoparticles. Magnetic properties of samples calcined with different calcination period were analyzed and both samples shown a transition temperature around 274 K.


2013 ◽  
Vol 678 ◽  
pp. 253-257 ◽  
Author(s):  
Thangaraj Pandiyarajan ◽  
B. Karthikeyan

In the present work we report, synthesis, structural, thermal and optical properties of ZnO incorporated PVP films. To prepare Polyvinylpyrolidone (PVP) capped ZnO films, simple room temperature sol gel method was adopted. Prepared PVP capped ZnO films were annealed at 800 C for 15 min and 30 min. X ray diffraction pattern shows prepared particles are in hexagonal wurtzite structure. Optical absorption measurements show an exciton absorption peak around ~ 370 nm. Emission spectra shows strong peaks around 329 and 333 nm are attributed to the band edge emission and broad peak found at 432 nm is attributed to the defect related emission. Thermal properties of the prepared films were studied by thermo gravimetric analysis. Interaction between the ZnO nanoparticles and PVP were investigated by Fourier Transform Infrared Spectroscopy (FTIR), it shows band at 441 cm-1 is attributed to Zn-O bond.


2011 ◽  
Vol 471-472 ◽  
pp. 1040-1045 ◽  
Author(s):  
Samaneh Shahgaldi ◽  
Zahira Yaakob ◽  
Dariush Jafar Khadem ◽  
Wan Ramli Wan Daud ◽  
Edy Herianto Majlan

In recent years, one dimensional nanostructure, nanowires, nanofibers with unique properties have been a subject of intense research due to reduction of devise dimension, potential properties from the re-arrangement at the molecular level and high surface area. There are many methods for synthesize such as laser ablation, chemical vapour deposition, solution method micro pulling down method but all these method faced to the major disadvantages of being complicated with long wasting time and relatively high expense . The electrospinning recently used for producing ceramic, metal, and carbon nanofibers. In this report, we incorporate palladium into silica nanofibers for the first time, and the effect of doping of palladium into the silica nanofibers is investigated. The different ratio of palladium to silica and comparing with silica nanofibers is also reported. The composition, morphology, structure and surface area of silica, and silica palladium nanofibers were investigated by thermo gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FT-IR), and Micromeriics. To the best of our knowledge, investigation on characteristic on Silica palladium nanofibers has not been reported up to now. The result reveal that the silica nanofibers compare to silica doped with palladium have lower diameter, and also by increasing the temperature above 600 °C, the reduction in length of nanofibers happened. High surface area of silica palladium nanofibers can be one of the promising materials for hydrogen storage.


Author(s):  
Guo-Bin Jung ◽  
Ting-Chu Jao ◽  
Chia-Chen Yeh ◽  
Ming-Hsien Huang ◽  
Wang-Shen Su

A series of Y0.2ZrxCe0.8−xO1.9 compounds (0 ≤ x ≤ 0.6) had been prepared by the modified sol-gel method and characterized by powder X-ray diffraction, thermo-gravimetric analysis, four-probe resistivity, and Vickers’s hardness studies. The gels from co-precipitation were treated with heated 1-octanol. All of the samples showed fluoride structure after calcined at 600 °C. Sintering the powders of Y0.2Ce0.8O1.9 and Y0.2Zr0.6Ce0.2O1.9 at 1300 °C gave the relative density of 95.8% and 99%, respectively. 99% relative density could be obtained for all samples after sintering at 1500 °C. This study showed a much more improved result than that of the previous reports. The hardness was 13.7 GPa for the Y0.2Zr0.6Ce0.2O1.9 pellet, which was twice greater than that for Y0.2Ce0.8O1.9 (7.1 GPa). Therefore, the mechanical properties could be improved by the addition of ZrO2 to Y0.2ZrxCe0.8−xO1.9. At 800 °C, the electrical conductivity of Y0.2Ce0.8O1.9 and Y0.2Zr0.6Ce0.2O1.9 were 3.3 × 10−2 S/cm and 5.5 × 10−3 S/cm, respectively. The conductivity was decreased by the addition of ZrO2 to Y0.2Ce0.8O1.9. It showed that the conductivity and hardness of Y0.2Zr0.2Ce0.6O1.9 were 1.2 × 10−2 S/cm and 9.6 GPa, respectively, at 800 °C and could be a better electrolyte candidate for “intermediate-temperature” unitized regenerative solid oxide fuel cells.


2021 ◽  
Vol 36 (1) ◽  
pp. 16-24
Author(s):  
O. A. Ajayi ◽  
S Nanbyen ◽  
A. A Oladipo ◽  
F. U. Nwafulugo

MIL-53(Fe)/Cow bone char composite, prepared via the sol-gel method was used for the removal of chromium from real tannery effluent having an initial concentration of 40mg/l. The characteristics of MIL-53(Fe)/Cow bone char were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA) Boehm titration and scanning electron microscopy (SEM-EDX). Adsorption capacity of MIL-53(Fe)/Cow bone char composite for chromium was 19.61 mg/g with a removal efficiency of 87.8% at an optimal bed height of 2.4cm (2.0g) for MIL-53(Fe)/Cow bone char composite, time of 2 minutes and pHpzc=5.4.The kinetic studies showed that the adsorption data were well fitted to the pseudo second-order model with high correlation coefficient R2=0.9911. Furthermore, the adsorption isotherm equilibrium studies confirmed that the Langmuir model best described the adsorption process of chromium onto MIL-53(Fe)/Cow bone char composite. Analysis of data with Dubinin–Radushkevich and Temkin isotherms showed that adsorption of chromium onto MIL-53(Fe)/Cow bone char composite is physical in nature.


2011 ◽  
Vol 364 ◽  
pp. 353-358
Author(s):  
Yin Chew Ker ◽  
Abu Bakar Mohamad

Quaternary metal oxide of Ba2NiTi5O13was synthesized by using two-step sol-gel method. Excess of titanium dioxide obtained from the first step of sol-gel synthesis, were subsequently reacted in second step of sol-gel synthesis in order to produce Ba2NiTi5O13monoclinic phase. Calcination temperature of 900 °C for as long as 8 hours was needed for obtaining pure phase of Ba2NiTi5O13. Homogenous micron sized particles of Ba2NiTi5O13with average size of 0.10 μm and narrow distribution were observed using Scanning Electron Microscopy (SEM). Besides, porous structures can also be seen distributed across the surface of the particles of Ba2NiTi5O13particles. Characterization of monoclinic phase of Ba2NiTi5O13was described based on the investigations of X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and Thermo Gravimetric Analysis (TGA).


2015 ◽  
Vol 1104 ◽  
pp. 3-8 ◽  
Author(s):  
Tong Qing Zhou ◽  
Ting Chen ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Xiao Jun Zhang ◽  
...  

Corundum structurealumina (α-Al2O3) powders were prepared via a non-hydrolytic sol-gel (NHSG) method using aluminum as raw material, ethanol as solvent, and iodine as catalyst. X-ray diffraction (XRD), differential thermal analysis (DTA), thermo gravimetric analysis (TG) were used to characterize the crystal phase of the products, while scanning electron microscopy (SEM) and transmission electron microscope (TEM) were employed to analyze the morphology. The results indicated that γ-Al2O3 was completely changed to α-Al2O3 at 1100 o C with a bit of aggregation. When 3 wt.% polyethylene glycol 600 (PEG 600) was introduced on the NHSG process, the dispersion was improved and the particle size decreased to100 nm.


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