Geometrical Study on Change of Pore Volume of MCM-41 Functionalized with Aminopropyl Groups

2007 ◽  
Vol 1056 ◽  
Author(s):  
Kenji Murakami ◽  
Kiyoshi Fuda ◽  
Mikio Sugai
Keyword(s):  
Mesoporous Silica ◽  
Pore Volume ◽  
Surface Density ◽  
Nitrogen Adsorption ◽  
Mesoporous Silicas ◽  
Functionalized Mesoporous Silica ◽  
Adsorption Desorption ◽  
Mcm 41

ABSTRACTMesoporous silicas functionalized with aminopropyl groups were synthesized by co-condensation of tetraethoxysilane (TEOS) and 3-aminopropyl triethoxysilane (APTES) and characterized by nitrogen adsorption-desorption measurements. The pore volume drastically decreased from about 900 mm3/g for the unfunctionalized mesoporous silica to about 300 mm3/g for the aminopropyl-functionalized mesoporous silica (1.65 mmol-NH2/g). This result was explained in terms of the surface density of the aminopropyl groups in the pore.

scholarly journals Synthesis, Characterization and Textural Analysis of Functionalized Mesoporous Silica Using Sodium Silicate as Precursor and Silicone Surfactant as Template

2014 ◽  
Vol 11 (2) ◽  
pp. 419-428
Author(s):  
Baghdad Science Journal
Keyword(s):  
Mesoporous Silica ◽  
Sodium Silicate ◽  
Nitrogen Adsorption ◽  
Average Diameter ◽  
Functionalized Silica ◽  
Average Pore ◽  
Force Microscopy ◽  
Functionalized Mesoporous Silica ◽  
One Step ◽  
Adsorption Desorption

Three mesoporous silica with different functional group were prepared by one-step synthesis based on the simultaneous hydrolysis and condensation of sodium silicate with organo - silane in the presence of template surfactant polydimethylsiloxane - polyethyleneoxide (PDMS - PEO). The prepared materials were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and nitrogen adsorption/desorption experiments. The results indicate that the preparation of methyl and phenyl functionalized silica were successful and the mass of methyl and phenyl groups bonded to the silica structure are 15, 38 mmol per gram silica. The average diameter of the silica particles are 103.51, 167.25 , and 86.41 nm while the average pore diameter are 6.7, 16.4, and 2.7 nm for unfunctionalized, methyl, and phenyl functionalized silica respectively.

Hydrothermal Biotemplated Synthesis of Amine-Functionalized Mesporous Silica and Adsorption Properties for Lead (II)

2013 ◽  
Vol 781-784 ◽  
pp. 1958-1962
Author(s):  
Li Jun Luo ◽  
Yong Liu ◽  
Qiao Ling Li ◽  
Jing Chi Mo
Keyword(s):  
Mesoporous Silica ◽  
Nitrogen Adsorption ◽  
Nitrogen Atmosphere ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Functionalized Mesoporous Silica ◽  
Measurement Results ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

By using natural bamboo as biotemplate, we synthesized mesoporous silica by Hydrothermal method followed by calcination at 650°C. And it was functionalized with aminopropyltriethoxysilane (APTS) in dry toluene under nitrogen atmosphere. As-synthesized Amino-functionalized mesoporous silica (NH2-MS) were characterized by scanning electron microscope (SEM), nitrogen adsorption/desorption (BET), Fourier transform infrared spectra (FT-IR).The results indicated that the obtained particles retained the morphology of bamboo and possessed mesoporous structrure. Adsorption measurement results indicates the Pb (II) adsorption isotherm fits Freundlich model and maximum adsorption capacity of 143.4mg/g, the pseudo second-order kinetic model provided the best fit to the experimental data.

scholarly journals Synthesis and Testing of Functional Mesoporous Silica Nanoparticles for Removal of Cr(VI) Ions From Water

2020 ◽  
Vol 11 (2) ◽  
pp. 8599-8607
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Porous Silica ◽  
Nitrogen Adsorption ◽  
Attenuated Total Reflection ◽  
Functionalized Mesoporous Silica ◽  
Adsorption Removal ◽  
Transmission Electron ◽  
Adsorption Desorption

This work reports a reliable and reproducible synthesis and in situ functionalization protocol for the synthesis of amino-functionalized mesoporous silica nanoparticles (MSNs). The porous amino-functional (pSiO2-NH2) nanoparticles were fully characterized by high-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and nitrogen adsorption-desorption (BET) analyses. The size of the particles was in the range of 80-200 nm with a specific surface area (SSA) of 721 m2 g-1, and the pore diameter was 31Å. The pSiO2-NH2 nanoparticles were tested for their efficiency in removing Cr(VI) ions from water. Almost quantitative removal of the ions was achieved by using the particles just within two hours. The adsorption efficiency of the particles was about 50 mg g-1. The synthesized porous silica particles can be repeatedly used as nano adsorbent for the adsorption removal of Cr(VI) ions from water. The nanoparticles can be potentially used for the selective capture, removal, and recovery of various other metal ions that can be complexed by amino groups.

scholarly journals Functionalized Ordered Mesoporous Silicas (MCM-41): Synthesis and Applications in Catalysis

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 617 ◽  
Author(s):  
Gabriel Martínez-Edo ◽  
Alba Balmori ◽  
Iris Pontón ◽  
Andrea Martí del Rio ◽  
David Sánchez-García
Keyword(s):  
Mesoporous Silica ◽  
Pore Structure ◽  
Metallic Nanoparticles ◽  
Mesoporous Silicas ◽  
Acid Catalysts ◽  
Catalytic Systems ◽  
Research Attention ◽  
Ordered Mesoporous ◽  
Regioselective Functionalization ◽  
Mcm 41

Mesoporous silica sieves are among the most studied nano-objects due to their stable pore structure and easy preparation. In particular, MCM-41 have attracted increasing research attention due to their chemical versatility. This review focuses on the synthesis and regioselective functionalization of MCM-41 to prepare catalytic systems. The topics covered are: mono and di-functionalized MCM-41 as basic and acid catalysts, catalysts based on metallic complexes and heteropolyacids supported onto MCM-41, metallic nanoparticles embed onto functionalized MCM-41 and magnetic MCM-41 for catalytic purposes.

scholarly journals Porosity Design of Shaped Zeolites for Improved Catalyst Lifetime in the Methanol-to-Hydrocarbons Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 545 ◽  
Author(s):  
Rogéria Bingre ◽  
Renna Li ◽  
Qiang Wang ◽  
Patrick Nguyen ◽  
Thomas Onfroy ◽  
...  
Keyword(s):  
Pore Volume ◽  
Active Sites ◽  
Coke Formation ◽  
Effective Diffusivity ◽  
Nitrogen Adsorption ◽  
Breakthrough Time ◽  
Methanol To Hydrocarbons ◽  
Catalytic Stability ◽  
Temperature Programmed ◽  
Adsorption Desorption

Additional porosity, such as meso- and macropores, was introduced in zeolite extrudates with the intention intuit of improving the effective diffusivity of the catalysts. The samples were characterized in depth by nitrogen adsorption-desorption, mercury intrusion porosimetry, ammonia temperature programmed desorption and adsorption of pyridine followed by infrared spectroscopy. The results revealed no significant change in the acidity but an increase of the pore volume. According to significant improvement in the effective diffusivity, the samples were tested in the methanol-to-hydrocarbons reaction. The catalytic stability was greatly enhanced with an increase in the pore volume, demonstrating a relation between effective diffusivity and resistance to deactivation by coke formation. Further experiments also revealed a higher toluene adsorption capacity and a raise in the breakthrough time over the most porous samples due to better accessibility of toluene molecules into the active sites of the zeolite.

Preparation of Mesoporous Silica from Rice Husk Ash: Effect of Depolymerizing Agents on Physico-Chemical Properties

2010 ◽  
Vol 93-94 ◽  
pp. 664-667 ◽  
Author(s):  
Supakij Suttiruengwong ◽  
P. Puathawee ◽  
M. Chareonpanich
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
Mesoporous Silicas ◽  
Organic Residues ◽  
Hydrophobic Property ◽  
Carbon Chains ◽  
Physico Chemical ◽  
Adsorption Desorption

The aim of this work was to prepare mesoporous silicas derived from rice husk ash (RHA) using three different depolymerizing agents; glycerol, 1,3 propanediol and 1,4 butanediol. The reaction of RHA with different depolymerizing agents was carried out between 200-250°C for 2 hrs. The solution was then hydrolyzed with deionized water to obtain gels. After a few washing step, gels were oven-dried and calcined at 500 °C for 24 hrs. Prepared mesoporous silicas were then characterized using Nitrogen adsorption-desorption measurement, FTIR, TGA, SEM, XRD and XRF. The percent hydrophobicity was determined based on the amount of moisture absorbed using TGA. It was shown that RHA reacted with depolymerizing agents above 200°C to form gels, which, after hydrolysis and calcination, still maintained the mesoporous characteristics. The BET and SEM results indicated that the RHA reacted with 1,3 propanediol had highest pore volume (0.95 cm3/g) and specific surface area (129.30 m2/g) compared to RHA reacted with glycerol and 1,4 butanediol. The distribution of pores computed from BJH desorption branch was also more uniform. FTIR indicated that there was no significant change in the chemical structure of RHA reacted with different depolymerizing agents. The residual C-H bands were found in FTIR spectra for all prepared mesoporous silicas. TGA thermograms confirmed the existence of organic residues (below 2 %wt), which might result from incomplete elimination even after calcination. This was found to be an important factor affecting the hydrophobic property of the reacted RHA. The hydrophobicity of RHA may be tailored by controlling depolymerizing agents and organic residues. Depolymerizing agents with longer carbon chains also favoured the hydrophobic characteristics.

Nanosized Titanium Oxynitride and Molybdenum Oxynitride Particles Assembled in Mesoporous Silica MCM-41

2006 ◽  
Vol 510-511 ◽  
pp. 138-141 ◽  
Author(s):  
Shan Zheng ◽  
Lian Gao
Keyword(s):  
Composite Materials ◽  
Mesoporous Silica ◽  
Mesoporous Materials ◽  
N2 Adsorption ◽  
Xps Spectra ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Nitridation Temperature ◽  
Mcm 41

Titanium oxynitride and molybdenum oxynitride assembled in the pores of mesoporous materials were achieved by nitriding titania-modified MCM-41 and molybdena-modified MCM-41 at 800°C for 3 hours under flowing NH3 atmosphere. XRD, XPS and N2 adsorption-desorption isotherms were employed to characterize the structure of the composite materials. The results showed that the nanosized TiOxNy and MoOxNy particles were assembled in mesoporous silica MCM-41 with the restrict mesopores. The hexagonal periodicity of the parent MCM-41 materials was maintained upon assembly at the provided nitridation temperature. The exact formation was TiO0.4N0.8 in MCM-TiOxNy, and MoO1.7N0.57 in MCM-MoOxNy, which were calculated from the data in XPS spectra of Ti 2p and Mo 3d.

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.

Efficient Removal of Cd2+ by the Mesoporous Silica Functionalized by APTES

2013 ◽  
Vol 726-731 ◽  
pp. 2409-2412
Author(s):  
Xiao Feng Cai ◽  
Kang Wei Ji ◽  
Wan Hao Wu ◽  
Jie Hou ◽  
Shi You Hao
Keyword(s):  
Aqueous Solution ◽  
Mesoporous Silica ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Efficient Removal ◽  
Structure Directing Agent ◽  
Functionalized Mesoporous Silica ◽  
Adsorption Desorption ◽  
Large Pore Size

Amino-functionalized mesoporous silica (AFMS) with high amino loading, high surface area, and large pore size was synthesized using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltriethoxysilane (APTES) as co-structure directing agent (CSDA). The synthesized AFMS was characterized by N2adsorption-desorption, TEM and elemental analyzer. The results of the removal of Cd2+from aqueous solution showed that the pH value of aqueous solution affected the removal efficiency of Cd2+greatly, and that unary adsorption isotherm of Cd2+on the AFMS was well described by the Sips isotherm model, in which the adsorption capacity was 2.43 mmol/g for Cd2+, much higher than the literature data.

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

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