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.

scholarly journals SYNTHESIS OF FUNCTIONALIZED MCM-41 MESOPOROUS SILICA

2017 ◽  
Vol 5 ◽  
pp. 1164-1168
Author(s):  
Nevin Karamahmut Mermer ◽  
Muge Sari Yilmaz
Keyword(s):  
Mesoporous Silica ◽  
Gas Sensing ◽  
Textural Properties ◽  
Mesoporous Molecular Sieve ◽  
Crystalline Materials ◽  
X Ray ◽  
Pure Silica ◽  
Significant Interest ◽  
Derivative Thermogravimetry ◽  
Mcm 41

: The invention of mesoporous materials is of significant interest to many scientists worldwide. The Mobil Crystalline Materials No 41 (MCM-41) is a well-known mesoporous molecular sieve that was discovered in 1992 by a scientist at the Mobil Oil Corporation. The MCM-41 is widely used in catalysis, ion exchange, drug delivery, optics, gas sensing, and sorption. In this study, the surface of a mesoporous silica MCM-41, synthesized from pure silica, is functionalized with a methyl group by grafting. The synthesized and functionalized samples are characterized by X-ray powder diffractometer (XRD), and the functionalized sample are also characterized by Fourier transform infrared spectroscopy (FTIR). The textural properties of the samples are determined using N2 adsorption and desorption analysis. Thermal behaviors of the samples are analyzed using thermogravimetry (TG) and derivative thermogravimetry (DTG). The results of the analyses show that the functionalization of the synthesized material through grafting was accomplished with the surface area of the functionalized sample determined as 600.87 m2 g-1.

Hydrotalcites with heterogeneous anion distributions: a first approach to producing new materials to be used as vehicles for the successive delivery of compounds

Clay Minerals ◽  
2020 ◽  
Vol 55 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Franchescoli D. Velázquez-Herrera ◽  
Geolar Fetter
Keyword(s):  
Microwave Irradiation ◽  
Divalent Cation ◽  
New Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Parameters ◽  
Crystallization Method ◽  
Anion Distribution

ABSTRACTHydrotalcites with heterogeneous distributions of anions between their layers were synthesized. Some synthesis parameters were studied to verify their influence on the anionic segregation properties of the hydrotalcites. The nature of the divalent cation and the crystallization method were most relevant. Zinc, in contrast to magnesium, assisted in discriminating carbonates and attracting nitrates to form hydrotalcites with heterogeneous distributions using microwave irradiation. Furthermore, the identification of this kind of hydrotalcite could be easily verified by determining the presence of a double reflection in the 003 X-ray diffraction (XRD) maximum, which definitively characterized a heterogeneous anion distribution. Finally, the reason as to why in some cases the hydrotalcite presented two reflections in the 003 XRD peak was elucidated.

scholarly journals Mesoporous Silica CoatedCeF3:Tb3+Particles for Drug Release

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Deyan Kong ◽  
Piaoping Yang ◽  
Zhenling Wang ◽  
Ping Chai ◽  
Shanshan Huang ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Fluorescence Spectra ◽  
Nitrogen Absorption ◽  
X Ray Diffraction ◽  
Green Fluorescence ◽  
Structure Directing Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Large Pore Volume ◽  
Desorption Isotherms

CeF3:Tb3+nanoparticles were successfully prepared by a polyol process using diethylene glycol (DEG) as solvent. After being coated with dense silica, theseCeF3:Tb3+nanoparticles can be coated with mesoporous silica using nonionic triblock copolymerEO20PO70EO20(P 123) as structure-directing agent. The composite can load ibuprofen and release the drug in the PBS. The composite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen absorption/desorption isotherms, fluorescence spectra, and UV/Vis absorption spectra, respectively. The composite particles have considerable large pore volume and large surface area. In addition, the composite still emits strong green fluorescence(Tb3+)and can be used as fluorescent probes in drug delivery system.

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

scholarly journals Microwave-Assisted Fabrication of Mesoporous Silica-Calcium Phosphate Composites for Dental Application

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 53
Author(s):  
Adrian Szewczyk ◽  
Adrianna Skwira ◽  
Marta Ginter ◽  
Donata Tajer ◽  
Magdalena Prokopowicz
Keyword(s):  
Calcium Phosphate ◽  
Mesoporous Silica ◽  
Octacalcium Phosphate ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Coating Solution ◽  
X Ray ◽  
Microwave Assisted ◽  
Calcium Orthophosphates ◽  
Different Types

Herein, the microwave-assisted wet precipitation method was used to obtain materials consisting of mesoporous silica (SBA-15) and calcium orthophosphates (CaP). Composites were prepared through immersion of mesoporous silica in different calcification coating solutions and then exposed to microwave radiation. The composites were characterized in terms of molecular structure, crystallinity, morphology, chemical composition, and mineralization potential by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDX). The application of microwave irradiation resulted in the formation of different types of calcium orthophosphates such as calcium deficient hydroxyapatite (CDHA), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP) on the SBA-15 surface, depending on the type of coating solution. The composites for which the progressive formation of hydroxyapatite during incubation in simulated body fluid was observed were further used in the production of final pharmaceutical forms: membranes, granules, and pellets. All of the obtained pharmaceutical forms preserved mineralization properties.

scholarly journals Portland clinker with civil construction waste: influence of pellet geometry on the formation of crystalline phases

2020 ◽  
Vol 20 (4) ◽  
pp. 205-223
Author(s):  
Fernanda Nepomuceno Costa ◽  
Daniel Véras Ribeiro ◽  
Cléber Marcos Ribeiro Dias
Keyword(s):  
Sustainable Development ◽  
Portland Cement ◽  
Rietveld Method ◽  
Industrial Process ◽  
3D Printer ◽  
New Materials ◽  
X Ray Diffraction ◽  
Construction Waste ◽  
X Ray ◽  
Portland Cement Association

Abstract Efforts to reduce greenhouse gas emissions in the context of sustainable development have intensified, with the development of research aimed at the production of new materials and binders for construction. This article analyzes the influence of pellet geometry in the production of clinkers, with the incorporation of construction waste (CCW). Procedures adapted from the method proposed by Brazilian Portland Cement Association were adopted in studies of laboratory clinkers, in an attempt to simulate the stages of the industrial process. Pellets were prepared with the same formulation, however, with four different geometries: spherical, with diameters of 1 cm, 2 cm and 3 cm, with manual molding, and semi-spherical, with a diameter of 2 cm, using molds of PLA (polylactic acid) printed on a 3D printer to facilitate the molding of the clinkers in a standardized way. Clinkers were characterized mineralogically by x-ray diffraction (XRD) and the Rietveld method was used to quantify the phases. Variations in the quantities of the alite and belite phases were observed depending on the geometry of the pellets, although the same calcination conditions were used. This is probably due to the variation in the surface area (exposure area) and the gradients of the cooling rate.

scholarly journals High Performance of Phenol Adsorption using Iron Based SBA-15 Synthesized by Loading-Microwave Method

2019 ◽  
Vol 35 (3) ◽  
pp. 1022-1028
Author(s):  
Yuvita Eka Pertiwi ◽  
Maria Ulfa
Keyword(s):  
Mesoporous Silica ◽  
Molecular Sieves ◽  
High Performance ◽  
Textural Properties ◽  
Hexagonal Structure ◽  
Kinetics Model ◽  
Element Analysis ◽  
Phenol Compounds ◽  
X Ray ◽  
Iron Based

The iron based mesoporous silica (Fe2O3/SBA-15) was studied for the first time for adsorption of phenol as a model adsorbate compound. The structural and textural properties of the synthesized samples were characterized by means of X-Ray Diffraction, Transmission Electron Microscopy, FTIR and element analysis techniques by Energy Dispersive X-Ray (EDX). The result of XRD analysis showed that mesoporous SBA-15 silica molecular sieves which modified with Fe2O3has a hexagonal structure with a pore size is 4.90 nm and iron contents (25.27%) were found on the surface of the Fe2O3/mesoporous silica SBA-15. While the FTIR analysis showed that Fe2O3/SBA-15 had functional group of assymetric Si-O-Si and Fe-O-Si which was found at 1085 cm-1 and 678 cm-1, respectively. Adsorption performance of Fe2O3/SBA-15 material investigated by phenol compounds as adsorbate model. The optimum contact time is 60 minutes and the Kinetics model of the mesoporous SBA-15 silica molecular sieves modified Fe2O3 can adsorb phenol compounds following the Kinetics Model Ho and McKay. The result optimum adsorption capacity occuring in the adsorption of phenol compounds by of the mesoporous SBA-15 silica molecular sieves modified Fe2O3 is 114.000 mg/g.

Metal-Controlled Assembly Tuning Coordination Polymers with Flexible 2-(1H-imidazole-1-yl)acetic Acid (Hima)

2006 ◽  
Vol 59 (9) ◽  
pp. 647 ◽  
Author(s):  
Yong-Tao Wang ◽  
Gui-Mei Tang ◽  
Da-Wei Qin
Keyword(s):  
Coordination Polymers ◽  
Weak Interactions ◽  
Critical Role ◽  
Three Dimensional ◽  
Supramolecular Network ◽  
Water Medium ◽  
New Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supramolecular Networks

Three new inorganic–organic coordination polymers based on a versatile linking unit 2-(1H-imidazole-1-yl)acetate (Hima) and divalent Mn(ii), Ni(ii), and Cu(ii) ions, exhibiting two kinds of two dimensionalities with different topological structures, have been prepared in water medium and structurally characterized by single-crystal X-ray diffraction analysis. Reaction of MnCl2·4H2O and Ni(NO3)2·6H2O with Hima yielded neutral two-dimensional (2D) coordination polymers [M(ima)2]n, M = Mn(ii) 1, and Ni(ii) 2 with isostructural 2D coordination polymers possessing (3,6) topology structures, which further stack into three-dimensional (3D) supramolecular networks through C–H···O weak interactions. However, when Cu(NO3)2·4H2O was used, a neutral 2D coordination polymer [Cu(ima)2]n 3 consisting of rhombus units was generated, which showed a 3D supramolecular network through C–H···O weak interactions. Among these polymers, the building block ima anion exhibits different coordination modes. These results indicate that the versatile nature of this flexible ligand, together with the coordination preferences of the metal ions, plays a critical role in construction of these novel coordination polymers. Spectral and thermal properties of these new materials have also been investigated.

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