scholarly journals Nanomaterial identification of powders: comparing volume specific surface area, X-ray diffraction and scanning electron microscopy methods

2019 ◽  
Vol 6 (1) ◽  
pp. 152-162 ◽  
Author(s):  
Claire Dazon ◽  
Olivier Witschger ◽  
Sébastien Bau ◽  
Vanessa Fierro ◽  
Philip L. Llewellyn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
X Ray Diffraction ◽  
Reliable Criterion ◽  
X Ray ◽  
Area X ◽  
Scanning Electron

This work shows that the volume specific surface area could be a reliable criterion for nanomaterial identification.

Structural and morphological features of MgO powders. The key role of the preparative starting compound

1998 ◽  
Vol 13 (8) ◽  
pp. 2218-2223 ◽  
Author(s):  
S. Ardizzone ◽  
C. L. Bianchi ◽  
B. Vercelli
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Starting Compound ◽  
Scanning Electron

The present paper reports data concerning magnesia samples obtained by calcination of different precursor salts at different increasing temperatures (873–1253 K). The oxides are characterized by x- ray diffraction, scanning electron microscopy, and N2 adsorption at subcritical temperatures. The samples appear to be composed, at any temperature, of pure periclase with a degree of crystallinity which increases with the temperature of calcination. Morphologically, the products have the shape either of lamellas or of cubes of variable dimensions, depending on the nature and route of preparation of the precursor salts. The variation of the specific surface area and the degree of porosity with the nature of the precursors and the temperature is discussed.

Effects of dry grinding on pyrophyllite

Clay Minerals ◽  
1988 ◽  
Vol 23 (4) ◽  
pp. 399-410 ◽  
Author(s):  
J. L. Pérez-Rodríguez ◽  
L. Madrid Sánchez del Villar ◽  
P.J. Sánchez-Soto
Keyword(s):  
Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Grinding Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Grinding ◽  
Scanning Electron ◽  
Area Data

AbstractDry grinding of pyrophyllite (Hillsboro, USA) has been studied by X-ray diffraction (XRD), specific surface area measurements (BET) and scanning electron microscopy (SEM). At the beginning of the grinding process, some effects such as delamination, gliding and folding of the layers, and decrease in particle size were detected by SEM and XRD, resulting in a large increase in specific surface area, up to a maximum of ∼60 m2·g−1. Marked changes in the structure take place between 30 and 32 mins grinding. Longer grinding times increase the degree of disorder and SEM and specific surface area data suggest that aggregation occurs. XRD results indicate that some residual order persists in the degraded structure.

Regeneration of the Brewing Spent Diatomite

2014 ◽  
Vol 998-999 ◽  
pp. 1425-1428 ◽  
Author(s):  
Wen Ya Mei ◽  
Teng Hong Hui
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Surface Area ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
X Ray ◽  
Remarkable Increase ◽  
Efficient Adsorbent ◽  
Scanning Electron

Brewing spent diatomite (BSDT), a beer industrial by-product, was regenerated with calcination. The characteristics of regenerated BSDT were detected by X-ray diffraction, X-ray fluorescence, Fourier-transform infrared, and scanning electron microscopy. The results showed that the mineralization of the surface adsorbate and the remarkable increase in the Si-OH decreased the pHpzc value from 7.6 to 5.2 and increased the surface area from 36 m2/g to 52 m2/g after calcination at 800 °C. The results show that the regenerated BSTD could be employed as an efficient adsorbent for the recycling of BSDT.

scholarly journals Selective Crystallization of Silicoalumophosphate Sapo-11 With A Micromesoporous Structure

2021 ◽  
Vol 9 (2) ◽  
pp. 109-111
Author(s):  
Zulfiya Khayrullina ◽  
Kanaan R. Ahmed ◽  
Samara Kambarova ◽  
Marat Agliullin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Molecular Sieve ◽  
Mesoporous Structure ◽  
Selective Crystallization ◽  
Scanning Electron

ABSTRACT:The authors have proposed a method for the selective crystallization of a SAPO-11 silicoaluminophosphate molecular sieve with a micro-mesoporous structure. It has been shown that crystallization of a silicoaluminophosphate gel, in the preparation of which its isopropoxide is used as a source of aluminum, makes it possible to obtain a SAPO-11 molecular sieve with a specific surface area of ​​~ 207 m2 / g, a volume of micro- and mesopores of ~ 0.08 and 0.09 cm3 / g. , respectively. Using scanning electron microscopy, it was demonstrated that the crystals of the material are pseudospherical particles ~ 8-10 microns in size, consisting of aggregates of nanocrystals ~ 100-200 nm in size.

scholarly journals Fabrication of Porous MoS2 with Controllable Morphology and Specific Surface Area for Hydrodeoxygenation

NANO ◽  
2017 ◽  
Vol 12 (09) ◽  
pp. 1750116 ◽  
Author(s):  
Zhenwi Zhang ◽  
Chuanjun Yue ◽  
Jianhen Hu
Keyword(s):  
Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Smooth Surface ◽  
High Selectivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Large Sheet

SiO2 nanoparticles modified with aminopropyl-triethoxysilane (APTES) were used as hard templates for preparing porous MoS2. The method offers the advantages of simple steps, convenient operation, controllable pore size, and a specific surface area. Two morphologies of MoS2 were obtained by using thiourea and L-cysteine as sulfur sources, respectively. Porous MoS2 prepared by using thiourea had a smooth surface, whereas the surface of porous MoS2 prepared with L-cysteine had many burrs. The MoS2 nanomaterials with the respective morphologies were used to catalyze the hydrodeoxygenation (HDO) reaction. The activity of MoS2 prepared with L-cysteine was lower than that prepared with thiourea. Transmission electron microscopy and X-ray diffraction analyses showed that MoS2 had a large sheet-shaped structure and high crystallinity, leading to high reaction activity and high selectivity for cyclohexane. The reaction temperature also influenced the HDO significantly. The mechanism of hydrogenation of phenol was discussed.

Sintering Sr2MgWO6 Ceramic and their Reactivity to Petroleum

2014 ◽  
Vol 798-799 ◽  
pp. 154-159 ◽  
Author(s):  
José Carlos da Silva Oliveira ◽  
Ricardo Arthur Sanguinetti Ferreira ◽  
Yogendra Prasad Yadava
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermogravimetric Analysis ◽  
Specific Surface ◽  
Ball Mill ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Microhardness ◽  
Scanning Electron

This work has as main objectives to produce the ceramic Sr2MgWO6and evaluate their reactivity to petroleum. Powders of SrCO3, MgO and WO3were selected, taken in stoichiometric amounts and synthesized by conventional route. The synthesis was characterized by size distribution, specific surface area and thermogravimetric analysis (TGA). The synthesis was also fragmented into ball mill and characterized by specific surface. It was compacted, then was calcined at 1200 °C and analyzed by X-ray diffraction. The powders Sr2MgWO6with perovskite structure were compacted and sintered at 1250, 1300 and 1350 °C. The materials produced were evaluated by microhardness, scanning electron microscopy (SEM), diffraction of X-rays and tests submersion in petroleum. The results showed that the ceramics have high microhardness and potential to be used in chemically aggressive environments such as petroleum.

A Comparative Study on Preparation of TiO2 Pellets as Photocatalysts Based on Different Precursors

2005 ◽  
Vol 475-479 ◽  
pp. 4165-4170 ◽  
Author(s):  
Yong Gang Luo ◽  
Linda Zou ◽  
Eric Hu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Area ◽  
Sintering Temperature ◽  
Temperature Reaction ◽  
Surface Porosity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Titania Powder ◽  
Scanning Electron

The porous TiO2 pellets were prepared based on pigment grade titaina, P25 titania powder and titanium(IV) butoxide. The characterization was done with X-Ray diffraction, scanning electron microscopy and BET measurements. The result shows that TiO2 pellets by using titanium(IV) butoxide with some addictive have the best surface porosity, with specific surface area of 196.9m2/g. For pigment grade titania and P25 titania powder, it is still effective to enhance the surface area after reassembling. The surface area increased from 11.6 to 29.2 m2/g for pigment grade titania and from 50 to 84.4 m2/g for P25 titania powder. Furthermore, it has been investigated on how to optimize and get the highest surface area by controlling the sintering temperature, reaction temperature, pH of solution, and the amount of alcohol and addictive of surfactant during preparation. The experimental photocatalytic degradation of acetone and toluene was performed using titania pellets made from P25 titania powder.

Rate of decay of specific surface area of snow during isothermal experiments and morphological changes studied by scanning electron microscopy

2003 ◽  
Vol 81 (1-2) ◽  
pp. 459-468 ◽  
Author(s):  
L Legagneux ◽  
T Lauzier ◽  
F Domin ◽  
W F Kuhs ◽  
T Heinrichs ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Specific Surface ◽  
Decay Rate ◽  
Surface Area ◽  
Specific Surface Area ◽  
Morphological Changes ◽  
Main Process ◽  
Snow Crystals ◽  
Scanning Electron

The quantification of the specific surface area (SSA) of snow crystals and of its variation during metamorphism are essential to understand and model the exchange of reactive gases between the snowpack and the atmosphere. Therefore, the decay rate of SSA of five fresh snow samples was studied in the laboratory at –4, –10, and –15°C under isothermal conditions in closed systems. The time-evolution of the snow SSA can in all cases be very well described by an empirical law of the form, SSA = – A log(t + Δt) + B, where A, B, and Δt are adjustable parameters. B seems to be closely related to the initial SSA of the snow, and A describes the SSA decay rate. Our preliminary findings at –15°C suggest that a linear relationship exists between A and B, so that it may be possible to predict the decay rate of snow SSA from its initial value. For the first time, images obtained from scanning electron microscopy show that crystal rounding of snow is the main process taking place during isothermal metamorphism. New grain boundaries also form. More surprising, however, was the formation of new basal, prismatic, and pyramidal crystal faces, sometimes with very sharp angles, especially at –15°C. The growth of facets with sharp angles is not fully explained by current theories of snow metamorphism and has not been observed before. PACS Nos.: 68.35Md, 68.37Hk, 81.20Ev, 81.05Rm

scholarly journals Effect of KOH Activator on the Performance of Activated Carbon from Oil Palm Kernel Shell as Supercapacitor Electrode Material

2020 ◽  
Vol 9 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Yola Azli Perdana ◽  
Rahma Joni ◽  
Emriadi Emriadi ◽  
Hemansyah Aziz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Activated Carbon ◽  
Surface Area ◽  
Palm Kernel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Palm Kernel Shell ◽  
Scanning Electron

Karbon aktif dari cangkang kelapa sawit sebagai bahan elektroda superkapasitor telah diteliti. Superkapasitor dirangkai dengan metoda plat/sandwich yang dipisahkan oleh separator. Untuk mendapatkan nilai kapasitansi yang besar dilakukan variasi jumlah aktivator terhadap karbon menggunakan aktivator KOH. Sifat fisikokimia dari karbon aktif diteliti dengan melakukan karakterisasi menggunakan XRD (X-Ray Diffraction), SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-Ray) dan SAA (Surface Area Analyzer) dan sifat elektrokimianya diteliti dengan pengukuran CV (Cyclic Voltammetry). Karbon aktif dengan perbandingan 1:5 memiliki luas permukaan yang paling besar yaitu 793,326 m2/g dan nilai kapasitansi spesifik tertinggi yaitu 99,151 F/g. The activated carbon from oil palm kernel shell as an electrode material for supercapacitors has been investigated. The supercapasitor was assembled by plate/sandwich methods. Both electrodes were separated by using a separator. To increase the capacitancy value, variations in the number of activators on carbon were carried out using KOH activator. The physicochemical properties of activated carbon were investigated by characterizing using XRD (X-Ray Diffraction), SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-Ray) and SAA (Surface Area Analyzer) and the electrochemical properties were investigated by measuring CV (Cyclic Voltammetry). Activated carbon with a ratio of 1:5 has the largest surface area of 793,326 m2/g and the highest specific capacitance value is 99,151 F/g.Keywords: activated carbon, supercapasitor, activator, surface area, specific capacitance

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