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.

Optimization by RSM of the degradation of three phenolic compounds – hydroquinone, resorcinol and catechol – on Fe-modified clays

2013 ◽  
Vol 48 (2) ◽  
pp. 171-179
Author(s):  
Manel Baizig ◽  
Bassem Jamoussi ◽  
Narjès Batis
Keyword(s):  
Phenolic Compounds ◽  
High Performance ◽  
Textural Properties ◽  
Response Surfaces ◽  
Operating Conditions ◽  
Iron Ions ◽  
X Ray Diffraction ◽  
Degradation Study ◽  
X Ray ◽  
Clay Catalysts

A Fenton-type wastewater treatment, using clay catalysts (montmorillonite and kaolinite), was prepared and used to degrade three phenolic compounds: hydroquinone, resorcinol and catechol. The operating conditions of the degradation of these compounds are optimized by the response surface methodology (RSM) which is an experimental design used in process optimization studies. The results obtained by the catalytic tests and analyses performed by different techniques (X-ray diffraction, volumetric adsorption, atomic absorption spectroscopy and high performance liquid chromatography (HPLC)) showed that the modified montmorillonites have very interesting catalytic, structural and textural properties; they are more effective for the catalytic phenolic compound degradation, they present the highest specific surface and they may support iron ions. We also determined the optimal degradation conditions by tracing the response surfaces of each compound; for example, for the catechol, the optimal conditions of degradation at pH 4 are obtained after 120 min at a concentration of H2O2 equal to 0.3 M. Of the three phenolic compounds, the kinetic degradation study revealed that the hydroquinone is the most degraded compound in the least amount of time. Finally, the rate of the catalyst iron ions release in the reaction is lower when the Fe-modified montmorillonites are used.

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 Effect of Surface Modifications of SBA-15 with Aminosilanes and 12-Tungstophosphoric Acid on Catalytic Properties in Environmentally Friendly Esterification of Glycerol with Oleic Acid to Produce Monoolein

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 360 ◽  
Author(s):  
Kullatida Ratchadapiban ◽  
Piyasan Praserthdam ◽  
Duangamol Tungasmita ◽  
Chutima Tangku ◽  
Wipark Anutrasakda
Keyword(s):  
Oleic Acid ◽  
Electrostatic Interactions ◽  
Heterogeneous Catalysts ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Hexagonal Structure ◽  
Tungstophosphoric Acid ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
X Ray

A series of protonated amino-functionalized SBA-15 materials was synthesized and tested as heterogeneous catalysts for the esterification of glycerol with oleic acid to produce monoolein. Mesoporous SBA-15 (S) was functionalized with three different aminosilanes: 3-aminopropyltriethoxysilane (N1); [3-(2-amino-ethylamino)propyltrimethoxysilane] (N2); and (3-trimethoxysilylpropyl) diethylenetriamine (N3), before being impregnated with 40 wt % 12-tungstophosphoric acid (HPW). The resulting nanocatalysts (S-Nx-HPW) were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption-desorption, SEM equipped with energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), and elemental analysis techniques. The presence of components of the nanocatalysts and the preservation of the hexagonal structure of SBA-15 were confirmed. Using different functionalizing agents considerably affected the textural properties and acidity of the synthesized nanocatalysts, which helped to improve the catalytic performance. In particular, S-N2-HPW was more active and selective than other catalysts in this study, as well as than a number of other commercial acid catalysts, with 95.0% oleic acid conversion and 60.9% monoolein selectivity being obtained after five h of reaction at 160 °C using 2.5 wt % of catalyst loading and glycerol/oleic acid molar ratio of 4:1. Aminosilane functionalization also helped to increase the reusability of the catalysts to at least six cycles without considerable loss of activity through strong electrostatic interactions between HPW anions and the protonated amino-functionalized SBA-15 materials.

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.

scholarly journals Boron and Nitrogen Co-Doped Porous Carbons Synthesized from Polybenzoxazines for High-Performance Supercapacitors

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 657 ◽  
Author(s):  
Bai ◽  
Ge ◽  
Bai
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Chemical Activation ◽  
Rate Capability ◽  
Weight Ratio ◽  
High Specific Capacitance ◽  
Porous Carbons ◽  
Element Analysis ◽  
X Ray ◽  
Co Doped

Boron and nitrogen co-doped porous carbons (BNPC-X) were synthesized from boron-containing polybenzoxazines through carbonization and chemical activation, where X represents the weight ratio of boric acid to benzoxazine resin. The as-prepared BNPC-X were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, element analysis and electrochemical measurements. The results show that the BNPC-0.15 possesses relatively high weight fractions of boron (2.97 wt %) and nitrogen (2.43 wt %), a homogeneous pore distribution, and remarkable electrochemical capacitive performance. It exhibits high specific capacitance (286 F·g−1 at 0.05 A·g−1), excellent rate capability (at A·g−1), and good charge–discharge stability (>92% capacitance retention after 1,000 cycles at 1.0 A·g−1) in 6 M KOH aqueous solution.

Small-angle X-ray scattering as a multifaceted tool for structural characterization of covalent organic frameworks

2020 ◽  
Vol 53 (5) ◽  
pp. 1376-1386
Author(s):  
Renata Avena Maia ◽  
Leonardo Simões de Abreu Carneiro ◽  
Jhonny Mauricio Cerón Cifuentes ◽  
Camilla Djenne Buarque ◽  
Pierre Mothé Esteves ◽  
...  
Keyword(s):  
Small Angle ◽  
Large Scale ◽  
Hierarchical Structures ◽  
Textural Properties ◽  
Hexagonal Structure ◽  
Nondestructive Method ◽  
Covalent Organic Frameworks ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Small-angle X-ray scattering (SAXS) is an accurate nondestructive method that requires a minimum of sample preparation and is employed to study porosity, morphology and hierarchical structures. Zeolites and silica are among the porous materials that are widely investigated by SAXS. However, studies of covalent organic frameworks (COFs) are still scarce. In the present study, SAXS was employed to investigate meso- and microporous COFs, affording insightful information about their nanostructure textural properties. SAXS is especially useful when combined with other characterization techniques, such as powder X-ray diffraction and N2 adsorption isotherms, emerging as an efficient tool to further characterize COFs. For microporous COFs, SAXS was used mainly to obtain quantitative values of surface roughness as a function of fractal parameters, in all cases indicating surface fractals of the large-scale scattering object, namely the `grain'. Mesoporous COF studies allowed elucidation of their hexagonal structure on the basis of their structure peaks; however, the main result lies in the distinction between the pore and the grain, which are described as a hierarchical structure by the Beaucage model and evaluated according to their fractality. These COFs generally exhibit pores with mass fractal features and grains with surface fractal features when they are submitted to post-functionalization, which may be due to the poor diffusivity of the functionalizing agents into the pores. In addition, a proposed aggregation description of the porous scattering objects was envisioned, based on small-angle scattering premises, which was confirmed for a microporous COF by high-resolution transmission electron microscopy.

Ordered 3D Hexagonal Mesoporous Silica Membranes: Synthesis and Characterization

2002 ◽  
Vol 752 ◽  
Author(s):  
Michaela Klotz ◽  
Sophie Besson ◽  
Christian Ricolleau ◽  
Florence Bosc ◽  
André Ayral
Keyword(s):  
Mesoporous Silica ◽  
Active Layer ◽  
Ceramic Membrane ◽  
Textural Properties ◽  
Hexagonal Structure ◽  
Synthesis And Characterization ◽  
Hexagonal Mesoporous Silica ◽  
Silica Membranes ◽  
Ordered Mesoporous ◽  
Hexagonal Network

ABSTRACTA ceramic membrane with an ordered mesoporous top layer has been developed. The active layer possesses a close-packed hexagonal network of spherical pores. Results on permeation of helium and argon through the membrane are presented and correlated with the structural and textural properties of the top layer. New insights are given on the porosity of this close-packed hexagonal structure.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

Computer programs for the calculation of x-ray intensities emitted by elements in multi-layer structures

1990 ◽  
Vol 48 (2) ◽  
pp. 216-217
Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers ◽  
J.M. Dijkstra
Keyword(s):  
Software Package ◽  
Light Element ◽  
Matrix Correction ◽  
Excellent Performance ◽  
Element Analysis ◽  
X Ray ◽  
Know How ◽  
Accurate Knowledge ◽  
Layer Structures ◽  
Bulk Matrix

For the calculation of X-ray intensities emitted by elements present in multi-layer systems it is vital to have an accurate knowledge of the x-ray ionization vs. mass-depth (ϕ(ρz)) curves as a function of accelerating voltage and atomic number of films and substrate. Once this knowledge is available the way is open to the analysis of thin films in which both the thicknesses as well as the compositions can usually be determined simultaneously.Our bulk matrix correction “PROZA” with its proven excellent performance for a wide variety of applications (e.g., ultra-light element analysis, extremes in accelerating voltage) has been used as the basis for the development of the software package discussed here. The PROZA program is based on our own modifications of the surface-centred Gaussian ϕ(ρz) model, originally introduced by Packwood and Brown. For its extension towards thin film applications it is required to know how the 4 Gaussian parameters α, β, γ and ϕ(o) for each element in each of the films are affected by the film thickness and the presence of other layers and the substrate.

An improved interference correction for trace element analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1646-1647
Author(s):  
John J. Donovan ◽  
Donald A. Snyder ◽  
Mark L. Rivers
Keyword(s):  
Trace Element Analysis ◽  
Accurate Estimate ◽  
Simple Expression ◽  
Standard Reference Materials ◽  
Characteristic Line ◽  
Analytical Line ◽  
Element Analysis ◽  
Electron Probe Analysis ◽  
Calculated Concentration ◽  
X Ray

We present a simple expression for the quantitative treatment of interference corrections in x-ray analysis. WDS electron probe analysis of standard reference materials illustrate the success of the technique.For the analytical line of wavelength λ of any element A which lies near or on any characteristic line of another element B, the observed x-ray counts at We use to denote x-ray counts excited by element i in matrix j (u=unknown; s=analytical standard; ŝ=interference standard) at the wavelength of the analytical line of A, λA (Fig. 1). Quantitative analysis of A requires an accurate estimate of These counts can be estimated from the ZAF calculated concentration of B in the unknown C,Bu measured counts at λA in an interference standard of known concentration of B (and containing no A), and ZAF correction parameters for the matrices of both the unknown and the interference standard at It can be shown that:

Sign in / Sign up

Export Citation Format

Share Document