A Novel Way to Synthesize Mesoporous Silica Coated on the CNTs with Larger Holes Based on “MCM-41” CNTs@SiO2

2011 ◽  
Vol 236-238 ◽  
pp. 1906-1909
Author(s):  
Wen Rui Zheng ◽  
Min Zhang ◽  
Jing Li Xu ◽  
Tao Huang
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Mesoporous Materials ◽  
High Efficiency ◽  
Low Cost ◽  
Novel Method ◽  
Mcm 41

We present a novel method to synthesize mesoporous nickel siliceous coated on CNTs with larger hole based on the mesoporous silica coated on CNTs, the pore size of mesoporous silica coated on CNTs was enlarged to 7.8 nm from 2.72 nm. Compared to others’ work, our method is low cost, simple and high efficiency. And more importantly, this method shows great potential in applying other type of mesoporous materials such as SBA-15 etc.

Positronium Thermalization Process in Nanoporous Materials and its Influence on the Shape of PALS Spectrum

2008 ◽  
Vol 607 ◽  
pp. 39-41
Author(s):  
Jerzy Kansy ◽  
Radosław Zaleski
Keyword(s):  
Mesoporous Silica ◽  
Pore Size Distribution ◽  
Porous Materials ◽  
Pore Size ◽  
Size Distribution ◽  
Nanoporous Materials ◽  
New Method ◽  
New Model ◽  
Conventional Models ◽  
Mcm 41

A new method of analysis of PALS spectra of porous materials is proposed. The model considers both the thermalization process of positronium inside the pores and the pore size distribution. The new model is fitted to spectra of mesoporous silica MCM-41 and MSF. The resulting parameters are compared with parameters obtained from fitting the “conventional” models, i.e. a sum of exponential components with discrete or/and distributed lifetimes.

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.

Novel Method for Soft Template Removal in the Synthesis of MCM-41 Mesoporous Materials

2003 ◽  
Vol 90-91 ◽  
pp. 79-84 ◽  
Author(s):  
Edit Meretei ◽  
Dóra Méhn ◽  
János Halász ◽  
Imre Kiricsi
Keyword(s):  
Mesoporous Materials ◽  
Soft Template ◽  
Template Removal ◽  
Novel Method ◽  
Mcm 41

scholarly journals Systematic Investigation of the Synergistic and Antagonistic Effects on the Removal of Pyrene and Copper onto Mesoporous Silica from Aqueous Solutions

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 546 ◽  
Author(s):  
Haiyan Li ◽  
Mengyun Zhai ◽  
Hongrui Chen ◽  
Chaohong Tan ◽  
Xiaoran Zhang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Mesoporous Silica ◽  
Pore Size ◽  
Average Pore Size ◽  
Adsorption Behavior ◽  
Ph Effects ◽  
Solution Ph ◽  
Antagonistic Effects ◽  
Mcm 41

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals have attracted greater attention due to their single or complex risks. It is urgent to find useful methods to remove these two pollutants together. In this study, SBA15 and MCM-41 were selected and used for the simultaneous removal of pyrene and copper from aqueous solution. Batch experiments were conducted systematically by investigating the adsorption behavior and effects including kinetics, isotherms, ionic strength and pH effects. Experimental results showed that the Langmuir and pseudo-second-order model fitted the adsorption behavior better. The solution pH values and ionic strength affected the adsorption behavior greatly. Furthermore, the synergistic or antagonistic effects could be observed on the adsorption of pyrene and copper onto MCM-41 and SBA15, respectively. The synergistic and antagonistic effects of pyrene and copper onto mesoporous silica may be attributed to the size of pyrene–copper complex and the average pore size of adsorbents. With the higher pore size, the complex would be adsorbed onto the inner surface of MCM-41 which showed synergistic effect on the adsorption of pyrene and copper. This study shows new guidelines and insight into the study of adsorption behavior of PAHs and heavy metals from aquatic environments.

scholarly journals Effect of preparation method on the properties of poly(methyl methacrylate)/mesoporous silica composites

2019 ◽  
Vol 2 (3) ◽  
pp. 363-370 ◽  
Author(s):  
M. A. Sibeko ◽  
M. L. Saladino ◽  
F. Armetta ◽  
A. Spinella ◽  
A. S. Luyt
Keyword(s):  
Thermal Stability ◽  
Mesoporous Silica ◽  
Methyl Methacrylate ◽  
Pore Size ◽  
Preparation Method ◽  
Polymer Chains ◽  
Melt Mixing ◽  
Poly Methyl Methacrylate ◽  
Mcm 41

Abstract The preparation method of a polymer composite and the filler loading are amongst the factors that influence the properties of the final composites. This article studies the effect of these factors on the thermal stability and thermal degradation kinetics of poly(methyl methacrylate) (PMMA)/mesoporous silica (MCM-41) composites filled with small amounts of MCM-41. The PMMA/MCM-41 composites were prepared through in situ polymerisation and melt mixing methods, with MCM-41 loadings of 0.1, 0.3, and 0.5 wt.%. The presence of MCM-41 increased the thermal stability of PMMA/MCM-41 composites prepared by melt mixing, but in the case of the in situ polymerised samples, the MCM-41 accelerated the degradation of the polymer. As a result, the activation energy was low and less energy was required to initiate and propagate the degradation process of these composites. The small-angle X-ray scattering (SAXS) measurements showed that the preparation method of the composites had no influence on the pore size of MCM-41, but the PMMAs used in the two methods both had shorter chains than the MCM-41 pore size. This allowed the polymer chains to be trapped inside the pores of the filler and be immobilised, as was observed from nuclear magnetic resonance (NMR) spectroscopy. The immobilisation of the polymer chains was more significant in the in situ polymerised samples.

Study on the Pore Size Expansion of Mesoporous Materials V-MCM-41 Using N, N-Dimethyl Formamide Amine

2013 ◽  
Vol 807-809 ◽  
pp. 365-368
Author(s):  
Fang Guo ◽  
Jun Qiang Xu ◽  
Jun Li
Keyword(s):  
Hydrothermal Synthesis ◽  
Pore Size ◽  
Mesoporous Materials ◽  
Cetyltrimethylammonium Bromide ◽  
Xrd Analysis ◽  
Treatment Temperature ◽  
Post Treatment ◽  
Dimethyl Formamide ◽  
Mcm 41 ◽  
Pore Expansion

The mesoporous materials with pore size expansion were synthesized by hydrothermal method with cetyltrimethylammonium bromide (CATB) as template. The N, N-dimethyl formamide (DMFA) amine was selected to expand the pore size of these materials. The samples were characterized by XRD, N2 adsorption and SEM. The pore size could be changed with post treatment temperature. The range of pore size was 3.94 - 5.83 nm. The pore size didn't increase with the increasing of post treatment temperature. The SEM pictures of materials with pore expansion by post-hydrothermal treatment clearly revealed that the resulting particles were almost perfectly spherical in shape. The XRD analysis showed the typical Bragg reflections of the hexagonal V-MCM-41 material by DMFA at 130 °C for 48 h in the post hydrothermal synthesis.

scholarly journals Rationalizing the role of the anion in CO2 capture and conversion using imidazolium-based ionic liquid modified mesoporous silica

RSC Advances ◽  
2015 ◽  
Vol 5 (79) ◽  
pp. 64220-64227 ◽  
Author(s):  
A. S. Aquino ◽  
F. L. Bernard ◽  
J. V. Borges ◽  
L. Mafra ◽  
F. Dalla Vecchia ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Mesoporous Silica ◽  
Mesoporous Materials ◽  
Co2 Capture ◽  
Imidazolium Chloride ◽  
Supported Ionic Liquids ◽  
Mcm 41

Covalently supported ionic liquids in mesoporous materials were prepared by grafting 1-methyl-3-(3-trimethoxysylilpropyl)imidazolium chloride in MCM-41.

Investigation of the silica pore size effect on the performance of polysulfone (PSf) mixed matrix membranes (MMMs) for gas separation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gholamhossein Vatankhah ◽  
Babak Aminshahidy
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Gas Separation ◽  
Gas Permeation ◽  
Mixed Matrix Membranes ◽  
Separation Performance ◽  
Mixed Matrix ◽  
Small Pore ◽  
Mcm 41 ◽  
Matrix Membranes

Abstract MCM-41 and SBA-15 mesoporous silica materials with different pore sizes (3.08 nm for small pore size MCM-41 (P 1), 5.89 nm for medium pore size SBA-15 (P 2), and 7.81 nm for large pore size SBA-15 (P 3)) were synthesized by the hydrothermal method and then functionalized with 3-aminopropyltrietoxysilane by postsynthesis treatments. Next, polysulfone-mesoporous silica mixed matrix membranes (MMMs) were prepared by the solution casting method. The obtained materials and MMMs were characterized by various techniques including X-ray diffraction, scanning electron microscopy, and N2 adsorption-desorption, and Brunauer-Emmett-Teller method to examine the crystallinity, morphology, and particle size, pore volume, specific surface area, and pore size distribution, respectively. Finally, the gas permeation rates of prepared MMMs were measured in 8 bar and 25 °C and the effect of pore size of modified and unmodified mesoporous silica on the gas separation performance of these MMMs were investigated. The experimental results indicate that the carbon dioxide (CO2) and methane (CH4) permeability and CO2/CH4 selectivity were increased with an enhancement in the particle pore size.

Synthesis of Mesoporous Silica from Tetraethylorthosilicate by Using Sodium Ricinoleic as a Template and 3-Aminopropyltrimethoxysilane as Co-Structure Directing Agent with Volume Variation of Hydrochloric Acid 0.1 M

2013 ◽  
Vol 789 ◽  
pp. 124-131 ◽  
Author(s):  
Andriayani Andriayani ◽  
Seri Bima Sembiring ◽  
Nida Aksara ◽  
Nofrijon Sofyan
Keyword(s):  
Electron Microscope ◽  
Mesoporous Silica ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Mesoporous Materials ◽  
X Ray ◽  
Volume Variation ◽  
Acid Addition ◽  
Imaging Results

Synthesis of mesoporous silica from tetraethylorthosilicate (TEOS) by using sodium ricinoleic as a template and 3-aminopropyltrimethoxysilane (APMS) as a co-structure directing agents (CDSA) in a volume variation of acid addition has been carried out. Preparation of mesoporous silica was conducted in HCl 0.1 M at volume variations of 2 ml, 35 ml, 40 ml and 50 ml. In acid conditions, the amine groups of APMS will protonate, which will then interact electrostatically with the carboxylate groups from ricinoleic acid, while the methoxy groups from APMS will condense with the silanol groups from TEOS to form an end product of mesoporous silica. The reaction products were characterized by using X-ray diffractometer (XRD), Fourier transform infra-red spectrometer (FTIR), surface area analyzer (BET), scanning electron microscope (SEM), and transmission electron microscope (TEM). X-ray diffractograms of the products from all of the acid volume variation additions show broadening peaks indicating amorphous materials as a characteristic of mesoporous materials. Infrared spectra show that all of the products have Si-OH and Si-O-Si groups that are characteristics for mesoporous silica. Imaging results from SEM and TEM show morphology and particle size differences in accordance with the differences in volume variation of acid addition. Adsorption/desorption isotherm by using nitrogen at 77 K of the products from the addition of 2 ml of HCl show an isotherm Type II (adsorption on the surface layer) with irregular pore size distribution, whereas from the addition of 30 ml, 35 ml, 40 ml and 50 ml HCl show an isotherm Type IV with a hysteresis loop that is characteristic for mesoporous materials with a regular pore size distribution.

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