Nitrogen Adsorption Analysis of Wood Saccharification Residues

ABSTRACTAdsorption and chemistry of tripropylphosphate (TPP) in mesoporous NaX zeolite, which was templated by cationic templated polymer (polydiallyldimethylammonium chloride, PDADMAC) with two different length chains, was investigated. The structural properties of the zeolites were characterized by X-ray diffraction (XRD) and nitrogen adsorption analysis. The chemical activities of different zeolites toward the decomposition of TPP were determined with solid state 31P NMR spectra. After exposure of zeolites to TPP was sufficient and equilibrium was reached, a stoichiometric amount of water was also adsorbed and hydrolysis was observed. The TPP decomposition yields in different NaX zeolites were compared.

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Preparation of Zirconia Nanofibers by Electrospinning and Calcination with Zirconium Acetylacetonate as Precursor

Polymers ◽

10.3390/polym11061067 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1067 ◽

Cited By ~ 5

Author(s):

Vyacheslav V. Rodaev ◽

Svetlana S. Razlivalova ◽

Andrey O. Zhigachev ◽

Vladimir M. Vasyukov ◽

Yuri I. Golovin

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Heterogeneous Catalysts ◽

Tetragonal Zirconia ◽

Nitrogen Adsorption ◽

Average Diameter ◽

High Specific Surface Area ◽

X Ray ◽

Adsorption Analysis

For the first time, zirconia nanofibers with an average diameter of about 75 nm have been fabricated by calcination of electrospun zirconium acetylacetonate/polyacrylonitrile fibers in the range of 500–1100 °C. Composite and ceramic filaments have been characterized by scanning electron microscopy, thermogravimetric analysis, nitrogen adsorption analysis, energy-dispersive X-ray spectroscopy, and X-ray diffractometry. The stages of the transition of zirconium acetylacetonate to zirconia have been revealed. It has been found out that a rise in calcination temperature from 500 to 1100 °C induces transformation of mesoporous tetragonal zirconia nanofibers with a high specific surface area (102.3 m2/g) to non-porous monoclinic zirconia nanofibers of almost the same diameter with a low value of specific surface area (8.3 m2/g). The tetragonal zirconia nanofibers with high specific surface area prepared at 500 °C can be considered, for instance, as promising supports for heterogeneous catalysts, enhancing their activity.

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Preparation of Large Carbon Nanofibers on a Stainless Steel Surface and Elucidation of their Growth Mechanisms

Zeitschrift für Naturforschung A ◽

10.1515/zna-2018-0323 ◽

2019 ◽

Vol 74 (3) ◽

pp. 253-258

Author(s):

M. R. Elamin ◽

Kamal K. Taha ◽

Babiker Y. Abdulkhair ◽

L. Khezami

Keyword(s):

Electron Microscopy ◽

Carbon Nanofibers ◽

Steel Substrate ◽

Chemical Vapour ◽

Nitrogen Adsorption ◽

Average Diameter ◽

Bet Surface Area ◽

Stainless Steel Surface ◽

Adsorption Analysis ◽

Steel Substrates

AbstractIn this work different shapes of carbon nanofibers (CNFs) were successfully synthesised on a treated commercial steel substrate by catalytic chemical vapour deposition (CCVD) utilising ethanol at 700 °C. The formation of the nanofibers with average diameter of 200–400 nm was confirmed via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The BET surface area, pore volume and pore size of the obtained CNFs were sequentially: 182 m2/g, 10.5 cm3/g and 103.3 Å as determined by nitrogen adsorption analysis. The influence of the surface treatment on the size and shape of CNFs was investigated and the results indicated a positive correlation that can be employed to tailor CNFs of desired morphology. Accordingly, a growth mechanism due to the deposition of carbonaceous materials on large size nanoparticles was proposed. As the CCVD is a facile and economical route for CNFs synthesis, thus, it can be efficiently adopted for the growth of CNFs on pretreated steel substrates as proved by this study.

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Adsorption of Toluene and Paraxylene from Aqueous Solution Using Pure and Iron Oxide Impregnated Carbon Nanotubes: Kinetics and Isotherms Study

Bioinorganic Chemistry and Applications ◽

10.1155/2017/2853925 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 18

Author(s):

Aamir Abbas ◽

Basim Ahmed Abussaud ◽

Ihsanullah ◽

Nadhir A. H. Al-Baghli ◽

Halim Hamid Redhwi

Keyword(s):

Carbon Nanotubes ◽

Aqueous Solution ◽

Iron Oxide ◽

Multiwall Carbon Nanotubes ◽

Freundlich Isotherm ◽

Nitrogen Adsorption ◽

Isotherm Models ◽

Batch Adsorption ◽

Adsorption Analysis ◽

Kinetics And Isotherms

Multiwall carbon nanotubes (CNTs) and iron oxide impregnated carbon nanotubes (CNTs-iron oxide) were investigated for the adsorption of hazardous toluene and paraxylene (p-xylene) from aqueous solution. Pure CNTs were impregnated with iron oxides nanoparticles using wet impregnation technique. Various characterization techniques including thermogravimetric analysis, scanning electron microscopy, elemental dispersion spectroscopy, X-ray diffraction, and nitrogen adsorption analysis were used to study the thermal degradation, surface morphology, purity, and surface area of the materials. Batch adsorption experiments show that iron oxide impregnated CNTs have higher degree of removal of p-xylene (i.e., 90%) compared with toluene (i.e., 70%), for soaking time 2 h, with pollutant initial concentration 100 ppm, at pH 6 and shaking speed of 200 rpm at 25°C. Pseudo-second-order model provides better fitting for the toluene and p-xylene adsorption. Langmuir and Freundlich isotherm models demonstrate good fitting for the adsorption data of toluene and p-xylene.

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An investigation of the fractal characteristics of the Upper Ordovician Wufeng Formation shale using nitrogen adsorption analysis

Journal of Natural Gas Science and Engineering ◽

10.1016/j.jngse.2015.07.023 ◽

2015 ◽

Vol 27 ◽

pp. 402-409 ◽

Cited By ~ 45

Author(s):

Lixi Liang ◽

Jian Xiong ◽

Xiangjun Liu

Keyword(s):

Nitrogen Adsorption ◽

Upper Ordovician ◽

Adsorption Analysis ◽

Fractal Characteristics

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Preparation of Organic-Inorganic Hybrid Materials Based on MCM-41 and Its Applications

Advances in Materials Science and Engineering ◽

10.1155/2013/634863 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Sana M. Alahmadi ◽

Sharifah Mohamad ◽

Mohd Jamil Maah

Keyword(s):

Mesoporous Silica ◽

Nitrogen Adsorption ◽

Toluene Diisocyanate ◽

Covalent Attachment ◽

X Ray Diffraction ◽

Channel System ◽

Modification Process ◽

Adsorption Analysis ◽

The Fourier Transform ◽

Mcm 41

This work reports the covalent attachment of three different calix[4]arenes (calix[4]arene (C4), p-sulfonatocalix[4]arene (C4S), and p-tert-butyl-calix[4]arene (PC4)) to MCM-41, using a three-step modification process. 3-Chloropropyltrimethoxysilane (ClPTS) was first attached to the mesoporous silica surface and subsequently converted to amides via the reaction with toluene diisocyanate (TDI). Finally, calix[4]arene derivatives attached to the isocyanate ending remained available on toluene di-iso-cyanate. Changes in the surface properties of the mesoporous silica caused by the chemical modification were monitored using the Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA), and elemental analysis. The FTIR spectra and TGA analysis verify that the calix[4]arene derivatives are covalently attached to the mesoporous silica. The preservation of the MCM-41 channel system was checked by the X-ray diffraction and nitrogen adsorption analysis. These materials were then used to evaluate the sorption properties of some organotins compounds (Tributyltin (TBT), Triphenyltin (TPT), and Dibutyltin (DBT)).

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Adsorption Properties of Self-Assembly Synthesized Microporous Silica Material from Acidic Aqueous Media

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.179-180.519 ◽

2011 ◽

Vol 179-180 ◽

pp. 519-522

Author(s):

Yan Yan Ji ◽

Biao Zhang ◽

Xiao Chun Wang

Keyword(s):

Self Assembly ◽

Aqueous Media ◽

Nitrogen Adsorption ◽

Adsorption Properties ◽

Relative Pressure ◽

Microporous Silica ◽

Acidic Aqueous Solution ◽

Silica Material ◽

Adsorption Analysis ◽

Volatile Organic

Microporous silica material AMPS has been synthesized via TEA+ cations assisted self-assembly of silica species in acidic aqueous solution. Nitrogen adsorption analysis revealed 0.65 nm uniform micropores in AMPS, companied with a Langmuir surface area of 745 m2/g and a pore volume of 0.22 cm3/g. The microporous AMPS exhibited an excellent adsorptive performance for volatile organic compounds (VOC) such as cyclohexane and acetone, compared with conventional zeolites such as Y, ZSM-5 and A. The adsorption was rapidly saturated at lower relative pressure with higher capacities than that of conventional zeolites. These features implied promising potentials in the separation and removal of VOCs in the atmosphere by using APS-3.

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Porous Ceramic Humidity Sensors Using Sol-Gel Processed ZrTiO4 Nanoparticles

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.45.1803 ◽

2006 ◽

Vol 45 ◽

pp. 1803-1808 ◽

Cited By ~ 1

Author(s):

I.C. Cosentino ◽

E.N.S. Muccillo ◽

F.M. Vichi ◽

R. Muccillo

Keyword(s):

Porous Ceramic ◽

Mercury Porosimetry ◽

Sol Gel ◽

Average Particle Size ◽

Nitrogen Adsorption ◽

Zirconium Oxychloride ◽

Average Particle ◽

Titanium Tetraisopropoxide ◽

X Ray Diffraction ◽

Adsorption Analysis

Ceramic ZrTiO4 powders were prepared by a sol-gel method using zirconium oxychloride and titanium tetraisopropoxide. In situ high temperature X-ray diffraction results show that crystallization of the amorphous gel starts at 400°C. Single-phase ZrTiO4 nanoparticles of 46 nm average particle size, determined by nitrogen adsorption analysis, were obtained after heat treatment at 450°C for 1 h. After pressing these sinteractive powders, pellets with controlled pore size distribution were obtained by sintering at temperatures as low as 400°C. The analysis of pores by mercury porosimetry gives an average porosity of 45%. The electrical resistivity, determined by impedance spectroscopy measurements at 24°C under different humidity environments, shows the ability of these pellets to adsorb water vapor in the porous surfaces.

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Fractals in carbon nanotube buckypapers

RSC Advances ◽

10.1039/c5ra23465d ◽

2016 ◽

Vol 6 (11) ◽

pp. 8639-8643 ◽

Cited By ~ 4

Author(s):

Chunyong Zhang ◽

Haiyan Cui ◽

Zhenzhu He ◽

Lin Su ◽

Degang Fu

Keyword(s):

Carbon Nanotube ◽

Nitrogen Adsorption ◽

Low Pressure ◽

Fractal Properties ◽

Adsorption Analysis ◽

Sem Imaging

Here, the fractal properties of buckypapers (BPs) have been initially studied by SEM imaging at different scales, as well as by low-pressure nitrogen adsorption analysis.

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TiCl4/MgCl2/MCM-41 Bi-Supported Ziegler–Natta Catalyst: Effects of Catalyst Composition on Ethylene/1-Hexene Copolymerization

Catalysts ◽

10.3390/catal11121535 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1535

Author(s):

Xiaoyu Liu ◽

Wenqi Guo ◽

Xueer Wang ◽

Yintian Guo ◽

Biao Zhang ◽

...

Keyword(s):

Active Center ◽

Supported Catalysts ◽

Nitrogen Adsorption ◽

X Ray Diffraction ◽

Activation Effect ◽

Catalyst Composition ◽

Adsorption Analysis ◽

Natta Catalyst ◽

Polymerization Conditions ◽

Mcm 41

TiCl4/MgCl2/MCM-41 type bi-supported Ziegler-Natta catalysts with different MgCl2/MCM-41 ratios were synthesized by adsorbing TiCl4 onto MgCl2 crystallites anchored in mesopores of MCM-41 (mesoporous silica with 3.4 nm pore size). Ethylene/1-hexene copolymerization with the catalysts was conducted at different 1-hexene concentrations and ethylene pressures. MgCl2/MCM-41 composite supports and the catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption analysis (BET), and elemental analysis. The copolymers were fractionated by extraction with boiling n-heptane, and comonomer contents of the fractions were determined. Under 4 bar ethylene pressure, the bi-supported catalysts showed higher activity and a stronger comonomer activation effect than the TiCl4/MgCl2 catalyst. In comparison with the TiCl4/MgCl2 catalyst, the bi-supported catalysts produced much less copolymer fraction of low molecular weight and high 1-hexene content, meaning that the active center distribution of the catalyst was significantly changed by introducing MCM-41 in the support. The copolymer produced by the bi-supported catalysts showed similar melting temperature to that produced by TiCl4/MgCl2 under the same polymerization conditions. The space confinement effect of the mesopores of MCM-41 on the size and structure of MgCl2 crystallites is proposed as the main reason for the special active center distribution of the bi-supported catalysts.

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