Characterization of tungstophosphoric acid supported on MCM-41 mesoporous silica using n-hexane cracking, benzene adsorption, and X-ray diffraction

2001 ◽  
Vol 207 (1-2) ◽  
pp. 159-171 ◽  
Author(s):  
Pasl A Jalil ◽  
Mohammed A Al-Daous ◽  
Abdul-Rahman A Al-Arfaj ◽  
Adnan M Al-Amer ◽  
Jorg Beltramini ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Tungstophosphoric Acid ◽  
Benzene Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mcm 41

Synthesis of SBA-15/MCM-41 bimodal mesoporous silica

2016 ◽  
Vol 1817 ◽  
Author(s):  
Leyla Y. Jaramillo ◽  
Wilson A. Henao ◽  
Elizabeth Pabón-Gelves
Keyword(s):  
Mesoporous Silica ◽  
Textural Properties ◽  
New Materials ◽  
X Ray Diffraction ◽  
Main Interest ◽  
Structure Directing Agent ◽  
X Ray ◽  
Synthesis Parameters ◽  
Nanostructured Silica ◽  
Mcm 41

ABSTRACTNanostructured silica materials with different morphologies and adjustable pore size have been studied by researches worldwide for several applications such as catalysis, separation, adsorption, and templates for new materials. The main interest in the development of these materials is to obtain a structure with a specific combination of pore sizes for a particular application. The morphology and textural properties of pores can be easily changed with the modification of the synthesis parameters, among these, the choice of surfactant or structure directing agent (SDA).Accordingly, in this work, three types of nanostructured silica with different mesoporosity were synthesized by using of CTAB and Pluronic 123 as structure directing agents: SBA-15 and MCM-41 unimodal mesoporous silica and SBA-15/MCM-41 bimodal mesoporous silica.To evaluate the effect of surfactant on the morphology and textural properties of pores, the materials were characterized by scanning electron microscopy (SEM), X-ray Diffraction (XRD) and nitrogen sorption (BET).

scholarly journals Simple Synthesis and Characterization of Hexagonal and Ordered Al–MCM–41 from Natural Perlite

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 264 ◽  
Author(s):  
Hongyun Chen ◽  
Siyao Fu ◽  
Liangjie Fu ◽  
Huaming Yang ◽  
Deliang Chen
Keyword(s):  
Mesoporous Silica ◽  
Bet Surface Area ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures ◽  
Ordered Mesoporous ◽  
Silica Materials ◽  
Mesoporous Silica Materials ◽  
Mcm 41

Silica reagents are expensive and toxic for use in the synthesis of mesoporous silica materials. It is imperative to take an interest in green silicon sources. In this paper, we report the synthesis of hexagonal and ordered aluminum-containing mesoporous silica materials (Al–MCM–41) from natural perlite mineral without addition of silica or aluminum reagents. A pretreatment process involving acid leaching, alkali leaching, and strongly acidic cation exchange resins treatment was critical to obtain silicon and aluminum sources from natural perlite mineral. The Al–MCM–41 material was synthesized via a hydrothermal reaction with hexadecyl trimethyl ammonium bromide (CTAB) as the template and subsequent calcination. The resulting mesophase had a hexagonal and ordered mesoporous structure, confirmed by small-angle X-ray diffraction (SAXRD) and transmission electron microscopy (TEM). Al–MCM–41 material had a high Brunauer–Emmet–Teller (BET) surface area of 1024 m2/g, pore volume of 0.72 cm3/g and an average pore diameter of 2.8 nm with a pore size distribution centered at 2.5 nm. The thermal behavior of the as-synthesized samples during calcination was investigated by thermogravimetry (TG) and differential thermogravimetry (DTG) analysis. The Al–MCM–41 material showed a negative surface charge in aqueous solution with the pH value ranging from 2 to 13. The variations of chemical structures from natural perlite to Al–MCM–41 were traced by wide-angle X-ray diffraction (WAXRD) and Fourier-transform infrared spectroscopy (FTIR). A proposed mechanism for the synthesis of hexagonal and ordered mesoporous silica materials from natural perlite is discussed.

Characterization of MCM-41 Mesoporous Silica Supported 2-Carboxyethyl Phenyl Phosphinic Acid

2013 ◽  
Vol 591 ◽  
pp. 134-137
Author(s):  
Zhi Dong Han ◽  
Feng Xu ◽  
Li Jiang ◽  
Zheng Quan Jiang ◽  
Peng Wang
Keyword(s):  
Mesoporous Silica ◽  
Energy Dispersive Spectrometer ◽  
Phosphinic Acid ◽  
Mesoporous Structure ◽  
Hydroxyl Group ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Mcm 41

MCM-41 mesoporous silica was prepared by hydrothermal method. 2-carboxyethyl phenyl phosphinic acid (CEPPA) was loaded on MCM-41 by solution method. The structure of MCM-41 and its supported CEPPA was studied by X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscopy (SEM) coupled with energy dispersive spectrometer (EDS). The results revealed that CEPPA was successfully loaded on MCM-41 with Si/P molar ratio of about 20:1. The XRD spectrum of MCM-41 supported CEPPA was different from MCM-41, indicating the structure of MCM-41 was changed after loading of CEPPA. CEPPA molecule moved into the mesoporous structure and filled in the mesopores, leading to the disappearance of characteristic diffraction peaks of MCM-41. The interaction between hydroxyl group of CEPPA and silanol of MCM-41 made it stable for CEPPA to be in the mesopores and on the surface of MCM-41. MCM-41 supported CEPPA also showed the similar mesoporous structure with long-range order to MCM-41 when observed by TEM. SEM provided further evidences of the similar particle size and different morphology.

Characterization of Highly Ordered MCM-41 Silicas Using X-ray Diffraction and Nitrogen Adsorption

Langmuir ◽  
1999 ◽  
Vol 15 (16) ◽  
pp. 5279-5284 ◽  
Author(s):  
Michal Kruk ◽  
Mietek Jaroniec ◽  
Ji Man Kim ◽  
Ryong Ryoo
Keyword(s):  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mcm 41

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Synthesis and characterization of TiN / Ti / AISI 410 coatings

2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama
Keyword(s):  
Synthesis And Characterization ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Columnar Grains ◽  
Tin Thin Films ◽  
Steel Aisi ◽  
Interacting Surfaces ◽  
Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

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