Alternative Silica Sources in the Synthesis of Ordered Mesoporous Silica

2021 ◽  
Vol 21 (5) ◽  
pp. 2847-2854
Author(s):  
Alessandra Scano ◽  
Federico Ebau ◽  
Valentina Cabras ◽  
Franca Sini ◽  
Guido Ennas
Keyword(s):  
Surface Area ◽  
Long Range ◽  
Fumed Silica ◽  
Biomedical Applications ◽  
Textural Properties ◽  
Ordered Mesoporous Silica ◽  
Structured Materials ◽  
X Ray ◽  
Ordered Mesoporous ◽  
Mcm 41

In this work, the influence of the use of alternative inexpensive silica sources on the structural, morphological and textural properties of MCM-41 like mesoporous materials to be used for biomedical applications has been investigated. The Liquid Crystal Template Method has been used to prepare the ordered mesoporous structured materials according to a novel composition starting from fumed silica or granular silica gel as alternative silica sources. The obtained materials have been characterized by X-ray Powder Diffraction, Transmission and Scanning Electron Microscopy, and nitrogen sorption, which showed for both samples the formation of the ordered hexagonal pore arrangement typical of a MCM-41 material. However, when using fumed silica, higher long-range hexagonal pore ordering as well as higher surface area have been obtained (1030 vs. 763 m2/g). For comparison, the features of a commercial silica mesostructured MCM-41 type have been investigated as well. Again, the silica fumed based sample has showed higher long-range hexagonal pore ordering, higher surface area and wall thickness. Preliminary stability studies on the fumed silica based material showed a decrease in the pore ordering at the end of the third year after the synthesis.

High specific surface area ordered mesoporous silica COK-12 with tailored pore size

2019 ◽  
Vol 280 ◽  
pp. 133-143 ◽  
Author(s):  
Laura M. Henning ◽  
Diego Díaz Cubas ◽  
Maria G. Colmenares ◽  
Johannes Schmidt ◽  
Maged F. Bekheet ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Ordered Mesoporous Silica ◽  
Ordered Mesoporous

Well-ordered mesoporous silica and bioactive glasses: promise for improved hemostasis

2019 ◽  
Vol 7 (1) ◽  
pp. 31-50 ◽  
Author(s):  
Sara Pourshahrestani ◽  
Nahrizul Adib Kadri ◽  
Ehsan Zeimaran ◽  
Mark R. Towler
Keyword(s):  
Mesoporous Silica ◽  
Textural Properties ◽  
Ordered Mesoporous Silica ◽  
Bioactive Glasses ◽  
Ordered Mesoporous

Mesoporous silica and bioactive glasses with unique textural properties are new generations of inorganic hemostats with efficient hemostatic ability.

scholarly journals Decolorization of Orange-G Aqueous Solutions over C60/MCM-41 Photocatalysts

2019 ◽  
Vol 9 (9) ◽  
pp. 1958 ◽  
Author(s):  
John Kyriakopoulos ◽  
Eleana Kordouli ◽  
Kyriakos Bourikas ◽  
Christos Kordulis ◽  
Alexis Lycourghiotis
Keyword(s):  
Ascorbic Acid ◽  
Azo Dye ◽  
Dye Degradation ◽  
Dye Adsorption ◽  
Fullerene C60 ◽  
Ordered Mesoporous Silica ◽  
Semiconducting Materials ◽  
Ordered Mesoporous ◽  
Orange G ◽  
Mcm 41

The majority of the photocatalysts studied for azo-dye degradation are based on semiconductor materials. Studies reported on non-semiconducting materials are very scarce. In the present work, we studied the fullerene (C60) ability to accelerate photodegradation of the dye’s azo bond in the presence of ascorbic acid. A series of C60 supported on ordered mesoporous silica (MCM-41) catalysts, containing 1, 3, 6, 9, and 12 wt % of fullerene C60, was studied using Orange G (OG) as representative azo-dye. This study showed that partial decolorization is achieved in the dark by simple adsorption of the dye on the bare surface of the carrier. The extent of decolorization increases with the irradiation of the suspension due to photocatalytic degradation of the azo-bond. This is maximized over the sample containing 3 wt % of C60 and it has been attributed to the best combination of the extent of the dye adsorption with the high intrinsic photocatalytic activity of small C60 clusters predominated in this sample. This catalyst proved to be quite stable upon five subsequent photocatalytic cycles, losing less than 5% of its initial activity. No degradation of OG takes place in the absence of ascorbic acid.

Adsorption of Carbon Dioxide into Amine Functionalized Ordered Mesoporous Materials

2018 ◽  
Author(s):  
Marcela N. Barbosa ◽  
Maria J. F. Costa ◽  
Maricele N. Barbosa ◽  
Valter J. Fernandes Jr. ◽  
Giancarlo R. Salazar-Banda ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Molecular Sieves ◽  
Synthesis Method ◽  
Mesoporous Molecular Sieves ◽  
Carbon Dioxide Adsorption ◽  
X Ray ◽  
Ordered Mesoporous ◽  
Mcm 41

The adsorption of carbon dioxide on amino silanes-functionalized MCM-41 and SBA-15 materials is reported. The functionalization of mesoporous silicas was made by post-synthesis method, by impregnation of 3-aminopropyltriethoxysilane. The obtained materials were characterized by X-ray diffraction, scanning and transmission electron microscopies, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy measurements. The carbon dioxide adsorption capacities for the samples were carried out under ambient pressures. The obtained results evidenced that amino-silanes with a terminal amine (–NH2) were functionalized through covalent coupling of this group on the surface of the channels in the ordered mesoporous silica, meaning that the amine is anchored on the surface of the bigger pores of the MCM-41 and SBA-15 support. For functionalized materials, the CO2 adsorption capacity of the AMCM-41 increased from 0.18 to 1.1 mmol·g−1, whereas for ASBA-15, it was from 0.6 to 1.8 mmol·g−1. The Lagergren kinetic algorithms were applied in order to validate the obtained results, evidencing the enhanced carbon dioxide adsorption capacity and stability of the functionalized ordered mesoporous molecular sieves.

scholarly journals Determination of toluene hydrogenation kinetics with neutron diffraction

2016 ◽  
Vol 18 (26) ◽  
pp. 17237-17243 ◽  
Author(s):  
Marta Falkowska ◽  
Sarayute Chansai ◽  
Haresh G. Manyar ◽  
Lynn F. Gladden ◽  
Daniel T. Bowron ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Mesoporous Silica ◽  
Ordered Mesoporous Silica ◽  
Total Neutron ◽  
Toluene Hydrogenation ◽  
Ordered Mesoporous ◽  
Hydrogenation Kinetics ◽  
Hydrogenation Of Toluene ◽  
Mcm 41

Total neutron scattering has been used to follow the hydrogenation of toluene-d8 to methylcyclohexane-d14 over 3 wt% platinum supported on highly ordered mesoporous silica (MCM-41) at 298 K and under 150–250 mbar D2 pressure.

scholarly journals Measuring the specific surface area of mesoporous silica using x-ray scattering

2014 ◽  
Vol 70 (a1) ◽  
pp. C599-C599
Author(s):  
Julien Cambedouzou ◽  
Olivier Diat
Keyword(s):  
Experimental Data ◽  
Specific Surface ◽  
Surface Area ◽  
Mesoporous Materials ◽  
Specific Surface Area ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Mcm 41 ◽  
Ray Scattering

The development of porous silica or carbon material with high specific surface area raises a high interest in the field of materials science given their potential interest in a wide range of applications including catalysis, water treatment or drug delivery. Among these mesoporous structures, those consisting of one-dimensional pores aligned along a compact hexagonal packing are of prime importance and can be referred to as "hexagonal mesoporous materials" (HMPM). The most famous silica structures of this kind are MCM-41 and SBA-15. The same symmetry can be found in carbon mesoporous materials, for example in FDU-15 structures. The precise characterization of HMPM is necessary for most of the applications envisioned for these materials (pore size, pore density, specific surface and sometimes thickness of the functionalization layer). Small angle X-ray scattering techniques offer the opportunity to determine the mean structural parameters of HMPM. Although different approaches can be found in the literature in order to numerically reproduce the experimental data obtained on HMPM or hexagonal liquid crystals, when the sample is a powder, fitting the experimental data in absolute scale with numerical models becomes necessary. However, with a large scattering contribution of grain at low q vector as well as short range correlation contribution at large q, the analysis is not so simple. In this paper, we propose a comprehensive study [1] devoted to the quantitative interpretation of small-angle scattering patterns of HMPM in terms of structure and specific surface estimation based on the formalism proposed by Spalla et al. [2]. In the case of two real samples, namely a SBA-15 and a MCM-41 powder, the specific surface area of the mesopores is estimated and is discussed in the light of gas adsorption measurements.

Templated self-assembly of ordered mesoporous silica on clay nanotubes

2019 ◽  
Vol 55 (38) ◽  
pp. 5507-5510 ◽  
Author(s):  
Aleksandr Glotov ◽  
Nikolay Levshakov ◽  
Anna Stavitskaya ◽  
Maria Artemova ◽  
Pavel Gushchin ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Self Assembly ◽  
Catalytic Properties ◽  
Ordered Mesoporous Silica ◽  
Ordered Mesoporous ◽  
Clay Nanotubes ◽  
Mcm 41

Self-assembly of ordered silica arrays on clay nanotubes resulted in mesoporous MCM-41 type materials with enhanced catalytic properties.

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