Characterization of mesoporous region by the scanning of the hysteresis loop in adsorption–desorption isotherms

Adsorption ◽  
2021 ◽  
Author(s):  
C. F. Toncón-Leal ◽  
J. Villarroel-Rocha ◽  
M. T. P. Silva ◽  
T. P. Braga ◽  
K. Sapag
Keyword(s):  
Hysteresis Loop ◽  
Desorption Isotherms ◽  
Adsorption Desorption

scholarly journals Synthesis and Characterization of Nanoporous Monetite Which Can Be Applicable for Drug Carrier

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Esmael Salimi ◽  
Jafar Javadpour
Keyword(s):  
Surface Area ◽  
Cetyltrimethylammonium Bromide ◽  
Drug Carrier ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Plate Shape ◽  
Desorption Isotherms ◽  
Adsorption Desorption

Wormhole-like mesostructured monetite was successfully synthesized using cetyltrimethylammonium bromide (C19H42BrN, CTAB), as a porosity agent. X-ray techniques and FTIR reveal that the crystalline grains consist of highly crystalline pure monetite phase. Monetite rods with diameter around 20–40 nm and length in the range of 50–200 nm were confirmed by FESEM and TEM. Based on N2adsorption-desorption isotherms investigation, surface area increased up to 31.5 m2/g due to the removal of surfactant after calcinations at 400°C. The results indicate that CTAB can not only affect monetite crystallization but also change particles morphology from plate shape to rod-like.

On the Texture Characterization of Mixed SiO2−ZrO2Aerogels Using the Nitrogen Adsorption−Desorption Isotherms:  Classical and Fractal Methods†

Langmuir ◽  
1997 ◽  
Vol 13 (5) ◽  
pp. 1145-1149 ◽  
Author(s):  
S. Blacher ◽  
R. Pirard ◽  
J. P. Pirard ◽  
B. Sahouli ◽  
F. Brouers
Keyword(s):  
Nitrogen Adsorption ◽  
Desorption Isotherms ◽  
Texture Characterization ◽  
Adsorption Desorption ◽  
Fractal Methods

Synthesis and Characterization of the Catalysts 5 wt.% and 10 wt.% Co/SBA-15

2010 ◽  
Vol 660-661 ◽  
pp. 561-566
Author(s):  
L.A. Lima ◽  
B.V. Sousa ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Ethylene Oxide ◽  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene Oxide ◽  
Desorption Isotherms ◽  
Poly Ethylene ◽  
Adsorption Desorption

Catalysts supported on SBA-15 were obtained by wet impregnation using aqueous solution of cobalt nitrate, where different contents of cobalt (5 wt% and 10 wt%) were prepared. The molecular sieve SBA-15 was synthesized using tetra ethyl ortho silicate (TEOS) as silicate source, and triblock copolymer, poly-(ethylene oxide)-poly (propylene oxide)-poly-(ethylene oxide) PEO-PPO-PEO as the organic structure directing agent. These materials were characterized by X-ray diffraction (XRD), X-ray energy dispersion spectrophotometer (EDX) and Nitrogen adsorption–desorption isotherms (BET). The results from the XRD showed that the molecular sieve mesoporous (SBA-15) was identified by X-ray diffraction, especially from the (210) and (300) peaks, which represent a typical spectrum for the SBA-15. Characterization of catalysts by Nitrogen adsorption–desorption isotherms (BET) made it possible to verify the the samples had been of type IV with hysteresis of corresponding the H2 type the porous materials.

Preparation and Characterization of Al-Pillared Rectorite

2010 ◽  
Vol 96 ◽  
pp. 129-133 ◽  
Author(s):  
Hong Yan Xu ◽  
Ai Hong Guo ◽  
Xing Tong Chen
Keyword(s):  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Narrow Pore Size Distribution ◽  
X Ray ◽  
Bet Specific Surface Area ◽  
Infra Red ◽  
Desorption Isotherms ◽  
Pore Properties ◽  
Adsorption Desorption

. Al-pillared rectorites (Al-REC) were synthesized from natural calcium rectorite through the exchange of inter-lamellar ions with hydroxyalumina polycations. Furthermore, the morphology, composite structure and pore properties of such composite materials were investigated by Powder X-ray Diffraction (XRD), Fourier Transformation Infra-red Spectra (FTIR) and Nitrogen Adsorption-Desorption Isotherms. The products retain their layered structure and their pore structures are a slit-shaped pore between plate-like particles. The resultant products possess BJH pore volume as large as 0.04cm3g-1, high BET specific surface area of over 100m2g-1, narrow pore size distribution in the mesopore region of 7-9nm after thermal treatment at 300 °C.

Synthesis and Characterization of Stable Mesoporous Multilamellar Silica Vesicles

2007 ◽  
Vol 121-123 ◽  
pp. 473-478 ◽  
Author(s):  
Yu Fang Zhu ◽  
Jian Lin Shi ◽  
Wei Hua Shen
Keyword(s):  
Pore Volume ◽  
Specific Area ◽  
Synthesis And Characterization ◽  
N2 Adsorption ◽  
Structure Directing Agent ◽  
Large Pore Volume ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
High Specific Area

A family of mesoporous multilamellar silica vesicles has been successfully synthesized by using P123 as structure directing agent and hexane as co-surfactant. The structure was characterized with XRD, TEM, and N2 adsorption-desorption isotherms. This multilamellar silica vesicle materials process high specific area, large pore volume, and a bimodale pore size distribution. Furthermore, these materials are stable when the surfactant is removed at 530 oC.

scholarly journals Extraction and Mass Spectrometric Characterization of Terpenes Recovered from Olive Leaves Using a New Adsorbent-Assisted Supercritical CO2 Process

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1301
Author(s):  
Zully J. Suárez Montenegro ◽  
Gerardo Álvarez-Rivera ◽  
Jose A. Mendiola ◽  
Elena Ibáñez ◽  
Alejandro Cifuentes
Keyword(s):  
Aluminum Oxide ◽  
Silica Gel ◽  
Supercritical Co2 ◽  
Olive Leaves ◽  
Fractionation Process ◽  
Selective Enrichment ◽  
Adsorption Desorption ◽  
First Time ◽  
By Products

This work reports the use of GC-QTOF-MS to obtain a deep characterization of terpenoid compounds recovered from olive leaves, which is one of the largest by-products generated by the olive oil industry. This work includes an innovative supercritical CO2 fractionation process based on the online coupling of supercritical fluid extraction (SFE) and dynamic adsorption/desorption for the selective enrichment of terpenoids in the different olive leaves extracts. The selectivity of different commercial adsorbents such as silica gel, zeolite, and aluminum oxide was evaluated toward the different terpene families present in olive leaves. Operating at 30 MPa and 60 °C, an adsorbent-assisted fractionation was carried out every 20 min for a total time of 120 min. For the first time, GC-QTOF-MS allowed the identification of 40 terpenoids in olive leaves. The GC-QTOF-MS results indicate that silica gel is a suitable adsorbent to partially retain polyunsaturated C10 and C15 terpenes. In addition, aluminum oxide increases C20 recoveries, whereas crystalline zeolites favor C30 terpenes recoveries. The different healthy properties that have been described for terpenoids makes the current SFE-GC-QTOF-MS process especially interesting and suitable for their revalorization.

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