Al-MCM-41 modified with carbonaceous deposits: characterisation by nitrogen adsorption measurements

2000 ◽  
Vol 2 (23) ◽  
pp. 5510-5516 ◽  
Author(s):  
Michal Rozwadowski ◽  
Maria Lezanska ◽  
Jerzy Wloch ◽  
Krzysztof Erdmann ◽  
Roman Golembiewski ◽  
...  
Keyword(s):  
Nitrogen Adsorption ◽  
Carbonaceous Deposits ◽  
Mcm 41

scholarly journals THE INFLUENCE OF Si/Al MOLE RATIO OF PRECURSOR SOLUTION ON THE STRUCTURAL PROPERTIES OF MCM-41 FROM FLY ASH

2010 ◽  
Vol 3 (2) ◽  
pp. 126-134
Author(s):  
Sutarno Sutarno ◽  
Yateman Arryanto ◽  
Stefani Wigati
Keyword(s):  
Fly Ash ◽  
Structural Properties ◽  
Sodium Silicate ◽  
Precursor Solution ◽  
Ammonium Hydroxide ◽  
Pore Wall ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Xrd Pattern ◽  
Mcm 41

The synthesis of MCM-41 from fly ash was done hydrothermally at 100°C for 72 hours using supernatant of fly ash solution, sodium silicate, tetramethylammonium hydroxide (TMAOH) and cetyltrimethyl-ammonium hydroxide (CTMAOH) surfactants. The effect of Si/Al mole ratio of precursor solution on the structural properties of MCM-41 was studied by variation of the volume composition of supernatant and sodium silicate. The surfactant was removed by calcination at 550°C for 5 hours with heating rate 2°C/minute. The as-synthesized products were characterized by X-ray diffraction, infrared spectroscopy, and nitrogen adsorption methods. The XRD pattern proved that the samples were MCM-41 and the higher the Si/Al mole ratio of precursor solution resulted MCM-41 with higher crystallinity. Calcination was able to remove the CTMAOH surfactant. It was identified by the disappearance of the peak at 3000-2850 cm-1, which is characteristic for CTMAOH. The XRD pattern of calcined MCM-41 showed the decrease of dspacing  and the increase of crystallinity. MCM-41 synthesized with Si/Al mole ratio of precursor solution=44.5 showed the highest crystallinity and has specific surface area=694.5 m2/g, average pore diameter=35Å and pore wall thickness=13.6Å.   Keywords: fly ash, Si/Al mole ratio, MCM-41, crystallinity

Rapid Synthesis of MCM-41 from Rice Husk Using Ultrasonic Wave: Optimation of Sonication Time

2019 ◽  
Vol 948 ◽  
pp. 198-205
Author(s):  
Suyanta Suyanta ◽  
Eko Sri Kunarti ◽  
Bambang Rusdiarso ◽  
Dritta Anies Cahaya ◽  
Efa Radnawati ◽  
...  
Keyword(s):  
Optimum Condition ◽  
Ultrasonic Wave ◽  
Rice Husk ◽  
Nitrogen Adsorption ◽  
Sonication Time ◽  
Ultrasound Waves ◽  
Comb Structure ◽  
Silica Source ◽  
Adsorption Desorption ◽  
Mcm 41

Ultrasound waves with 48 KHz of frequency were applied for the synthesis of MCM-41 using rice husk as the silica source. The effect of sonication time (30, 60, 90, 120, 150, 180, and 210 min) on the crystallinity of calcined MCM-41 was investigated. Characterization using XRD and FTIR indicated that the ordered structure of MCM-41 could be synthesized by ultrasonic wave. Sonication time at 150 min was found to be the optimum condition. The nitrogen adsorption-desorption isotherms informed that the mesoporous material produced at the optimum condition has 794.73 m2·g-1of surface area, 3.02 nm of BJH pore diameter, 1.17 nm of wall thickness, and 0.68 ml·g-1 of pore volume. While based on the TEM image, the material has hexagonal or a honey-comb structure.

Determination of the Lamellar Phase Content in MCM-41 Using X-ray Diffraction, Nitrogen Adsorption, and Thermogravimetry

2000 ◽  
Vol 104 (7) ◽  
pp. 1581-1589 ◽  
Author(s):  
Michal Kruk ◽  
Mietek Jaroniec ◽  
Yong Yang ◽  
Abdelhamid Sayari
Keyword(s):  
Nitrogen Adsorption ◽  
Lamellar Phase ◽  
Phase Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mcm 41

Catalytic Activity of Argentum-loaded MCM-41 for Ozonation of p- Chlorobenzoic Acid (p-CBA) in Aqueous Solution

2015 ◽  
Vol 18 (1) ◽  
Author(s):  
Zhaoqi Pan ◽  
Junyu Zeng ◽  
Bingyan Lan ◽  
Laisheng Li
Keyword(s):  
Aqueous Solution ◽  
Nitrogen Adsorption ◽  
Hexagonal Structure ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Chlorobenzoic Acid ◽  
Transmission Electron ◽  
Initial Ph ◽  
Adsorption Desorption ◽  
Mcm 41

AbstractArgentum-loaded MCM-41 (Ag/MCM-41) was synthesized successfully by a hydrothermal method and used as a catalyst for the ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution. Ag/MCM-41 was characterized by low angle X-ray diffraction (XRD), nitrogen adsorption-desorption and transmission electron microscopy (TEM). Characterizations suggest that the prepared samples retained a highly regulated mesopores of hexagonal structure and a high BET surface area. The influences of argentum content, initial pH, reaction temperature on the catalytic ozonation were also evaluated. Ag/MCM-41/O

Synthesis and Characterization of Mesoporous Molecular Sieve Al-MCM-41 Using Kaolin as Raw Material

2013 ◽  
Vol 779-780 ◽  
pp. 201-204
Author(s):  
Miao Li ◽  
Hong Wang ◽  
Xian Qing Li ◽  
Jin Rong Liu
Keyword(s):  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
Mesoporous Molecular Sieve ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Calcined Kaolin ◽  
Mcm 41

Ordered hexagonally mesoporous molecular sieve Al-MCM-41 with Si/Al (atom) ratio=9 was prepared by hydrothermal synthesis using raw kaolin. X-ray diffraction (XRD), Nitrogen adsorption desorption, Transmission Electron Microscope (TEM) and Energy Dispersive X-ray Detector (EDX) were employed to characterise raw kaolin, calcined kaolin, as-synthesized and calcined Al-MCM-41. The results indicated that characteristic reflections of raw kaolin disappeared after calcination, both of as-synthesized and calcined Al-MCM-41 exhibited well ordered hexagonally mesoporous molecular sieve structure.

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

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
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)).

scholarly journals Influence of Ethanol Concentration and Template Ion Exchange Agent on Template Recycling in Mobil Crystalline Material 41 (MCM-41) Synthesis

2020 ◽  
Vol 19 (2) ◽  
pp. 130
Author(s):  
Jia Yen Lai ◽  
Lock Hei Ngu ◽  
Farouq Twaiq
Keyword(s):  
Ion Exchange ◽  
Ethanol Concentration ◽  
Nitrogen Adsorption ◽  
Crystalline Material ◽  
Hexadecyltrimethylammonium Bromide ◽  
Water Mixture ◽  
Extract Solution ◽  
Exchange Agent ◽  
Synthesis Solution ◽  
Mcm 41

Recycling of surfactant template for several subsequent MCM-41 synthesis is necessary to reduce substantial synthesis solution disposal. In MCM-41 synthesis, ethanol concentration and template ion exchange agent are two significant factors that affect the silicate polymerization, solvating effect on micelles formation, and MCM-41 mesostructure formation. In view of that, this study investigates recycling of surfactant template ions in extract solution in Mobil Crystalline Material 41 (MCM-41) synthesis. Effect of the ethanol concentrations in the solution gel and the types of ion exchange agents on the yield of MCM-41 material and its surface morphology were studied. Hexadecyltrimethylammonium bromide was used as template for MCM-41 synthesis using tetraethylorthosilicate (TEOS) as silica reagent with ethanol-water mixture as solvent at different ethanol concentrations. Template ions of synthesis gel was exchanged with an ion exchange agent (i.e., 1-butyl-3-methylimidazolium chloride or ammonium nitrate) before it is extracted using synthesis solution. After extraction, the extracting solution was added with TEOS, used for second synthesis cycle and the process continued in an extraction. The template ions in the extract solution were further recycled up to eight synthesis cycles. Yield of calcined materials significantly influenced by ethanol solvent concentrations and however did not vary with various ion exchange agents. Nitrogen adsorption isotherms showed that the calcined materials exhibit MCM-41 characteristics with surface areas ranging from 600 – 1000 m2/g. It is possible to recycle and reuse the surfactant template for several subsequent times of preparing MCM-41 if the ethanol concentration in the solution gel controlled continuously.

INTRODUCTION OF A DOUBLE BOND CONTAINING MODIFIER ON THE SURFACE OF MCM-41 NANOPARTICLES: APPLICATION FOR SR&NI ATRP OF STYRENE

NANO ◽  
2014 ◽  
Vol 09 (02) ◽  
pp. 1450023 ◽  
Author(s):  
KHEZROLLAH KHEZRI ◽  
VAHID HADDADI-ASL ◽  
HOSSEIN ROGHANI-MAMAQANI
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
Mesoporous Silica Nanoparticles ◽  
Nitrogen Adsorption ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Scanning Calorimetry ◽  
Morphological Studies ◽  
Exclusion Chromatography ◽  
Mcm 41

Mesoporous silica nanoparticles (MCM-41) surface was functionalized with 3-(trimethoxysilyl)propyl methacrylate (MPS). Then, the resultant double bond containing nanoparticles were used in grafting through simultaneous reverse and normal initiation technique for atom transfer radical polymerization (SR&NI ATRP) of styrene to synthesize well-defined polystyrene nanocomposites with twofold chains. Nitrogen adsorption/desorption isotherm and X-ray diffraction analysis were used to evaluate characteristics of spherical MCM-41 nanoparticles. Morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography respectively. Addition of MCM-41 nanoparticles by 3 wt.% results in a decrease of conversion from 93% to 82%. Molecular weight of the free and attached polystyrene chains decreases by adding 3 wt.% MCM-41 nanoparticles; however, PDI values increases from 1.27 to 1.78 for free chains and 1.87 to 2.48 for attached chains. A peak around 4.1 ppm which originates from hydrogen atom of terminal units of polystyrene chains in proton nuclear magnetic resonance spectra in combination with low PDI values can appropriately demonstrate the living nature of the polymerization. Increasing thermal stability of the nanocomposites is demonstrated by Thermogravimetric analysis. Differential scanning calorimetry also shows a decrease in glass transition temperature by increasing MCM-41 nanoparticles.

scholarly journals Isosteric Heat: Comparative Study between Clausius–Clapeyron, CSK and Adsorption Calorimetry Methods

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 203 ◽  
Author(s):  
Liliana Giraldo ◽  
Paola Rodriguez-Estupiñán ◽  
Juan Carlos Moreno-Piraján
Keyword(s):  
Activated Carbon ◽  
Nitrogen Adsorption ◽  
Isosteric Heat ◽  
High Dispersion ◽  
Complex Nature ◽  
Calorimetric Study ◽  
Adsorption Calorimetry ◽  
Textural Characteristics ◽  
Textural Characterization ◽  
Mcm 41

This work presents the calorimetric study of five adsorbents with different chemical and textural characteristics: MOF-199, MCM-41, SBA-15, activated carbon prepared from corn cob (GACKP) and graphite. These solids were used to establish the differences between isosteric heats evaluated by three different methods: Clausius–Clapeyron (C-C), Chakraborty, Saha and Koyama (CSK) and Adsorption Calorimetry (A-Cal). The textural characterization results show solids that have values of specific surface area between 2271 m2·g−1 for the MOF-199 and 5.2 m2·g−1 for the graphite. According to the results obtained for the isosteric heats for each sample, the magnitude varies depending on the coverage of the adsorbate and the textural characteristics of each adsorbent. Solids with an organized structure have isosteric heat values that are coincident among the three methods. Meanwhile, heterogeneous solids such as activated carbon values evaluated by the CKS and C-C have a high dispersion method regarding the adsorption calorimetry method. The results obtained show that the adsorption calorimetry, being a direct experimental measurement method, presents less dispersed data. At low quantities, the isosteric heat of nitrogen adsorption decreased in the order MOF-199, GACKP, MCM-41, SBA-15 and Graphite. The order for the isosteric heats values was coherent with the surface characteristics of each of the solids, especially with the pore size distribution. Finally, throughout the coverage examined in this work, the isosteric heats for nitrogen adsorption determined by adsorption calorimetry (A-Cal) were larger than the evaluated by C-C and CSK indirect methods of vaporization. According to the results, it is shown that the adsorption calorimetry allows values of the isosteric heats of adsorption with an error of less than 2% to be established and also reveals the complex nature of the heterogeneity or homogeneity of the adsorbent.

Sign in / Sign up

Export Citation Format

Share Document