Carbon Dioxide Retention on Bentonite Clay Adsorbents Modified by Mono-, Di- and Triethanolamine Compounds

2014 ◽  
Vol 917 ◽  
pp. 115-122 ◽  
Author(s):  
Ali E.I. Elkhalifah ◽  
Mohammad Azmi Bustam ◽  
Mohd Shariff Azmi ◽  
T. Murugesan

A series of organic-inorganic hybrids were developed via intercalation process of primary, secondary and tertiary ammonium cations into different alkali and alkaline earth and transition metal cation forms of bentonite clay to be used as adsorbent materials for CO2capture under ambient temperature and slightly high pressure. The effect of the molar mass of amines on the structural characteristics, surface properties and CO2loading capacity of bentonite clay were investigated by X-ray diffraction, Brunauer-Emmett-Teller method and Magnetic Suspension Balance equipment, respectively. X-ray diffraction results revealed that the basal spacing of bentonite clay after modification with amines was increased with the molar mass of amine used, while BET results showed an inverse effect of the molar mass of amines on the surface area of the synthesized materials. The CO2loading capacity of the examined samples revealed that bentonite clay modified with monoethanolammonium cations retained higher CO2amount compared to those modified with di-and triethanolammonium cations. CO2adsorption isotherms on MEA+-Mg-MMT were conducted at 298, 323 and 348 K and different pressures. A decrease in CO2uptake with increasing temperature was observed, suggesting the exothermic nature of the adsorption process.

2021 ◽  
Vol 7 (5) ◽  
pp. 2010-2018
Author(s):  
Olukayode Gideon Oloyede ◽  
◽  
Umar Omeiza Aroke ◽  
Saidat Olanipekun Giwa ◽  
Alexander Asanja Jock ◽  
...  

In this study, Dijah-Monkin bentonite clay was modified with a cationic surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) at the level of twice the cation exchange capacity (CEC). This process results in the development of hydrophobic organoclay with an improved adsorption capacity. The clay obtained from Zing LGA Taraba State, North-East Nigeria, was beneficiated and pulverised to a particle size of 125 µm. The modification was performed without acid activation to prevent damages to the clay’s crystal structure. The organoclay was characterised for chemical composition, functional groups, mineralogical and surface morphology using X-ray fluorescence (XRF), Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD showed an increase in the basal spacing from 15.681Å to 17.758 Å, while the XRF revealed a 5.35% concentration of Br on the modified clay, indicating successful intercalation. The FTIR spectra also revealed the appearance of symmetric and asymmetric stretching bands at 2847.7cm-1 and 2914.8cm-1, respectively, as a consequence of the modification, resulting in more sites for adsorption.


2012 ◽  
Vol 727-728 ◽  
pp. 1780-1784
Author(s):  
Sara Verusca de Oliveira ◽  
Milena Costa da Silva ◽  
Gustavo Figueiredo Brito ◽  
Antônio Gilson Barbosa de Lima ◽  
Edcleide Maria Araújo

This research is to obtain nanocomposites of HDPE/bentonite clay. Inorganic polymers reinforced with materials are of great interest due to their applications in automotive, and electrical and electronic industries. The nanocomposites were produced by melt intercalation with different percentages of clay and compared with pure HDPE. Clay was used as modified and unmodified and it was characterized by X-ray diffraction (XRD) and X-ray fluorescence (XRF). The obtained nanocomposites were characterized through thermogravimetry (TG). It was verified by XRF that clay performed compositions of bentonites characteristics. By XRD, it was observed increases basal spacing for organoclay. By TG, in general, it was verified that the nanocomposites presented greater thermal stability in relation to HDPE.


Author(s):  
R. Gronsky

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.


Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 507 ◽  
Author(s):  
Maxim Rudmin ◽  
Elshan Abdullayev ◽  
Alexey Ruban ◽  
Ales Buyakov ◽  
Bulat Soktoev

We investigated the mechanochemical synthesis of complex slow release fertilizers (SRF) derived from glauconite. We studied the effectiveness of the mechanical intercalation of urea into glauconite using planetary and ring mills. The potassium-nitric complex SRFs were synthesized via a mechanochemical method mixing glauconite with urea in a 3:1 ratio. The obtained composites were analyzed using X-ray diffraction analysis, scanning electron microscopy, X-ray fluorescence analysis, and infrared spectroscopy. The results show that as duration of mechanochemical activation increases, the mineralogical, chemical, and structural characteristics of composites change. Essential modifications associated with a decrease in absorbed urea and the formation of microcrystallites were observed when the planetary milling time increased from 5 to 10 min and the ring milling from 15 to 30 min. Complete intercalation of urea into glauconite was achieved by 20 min grinding in a planetary mill or 60 min in a ring mill. Urea intercalation in glauconite occurs much faster when using a planetary mill compared to a ring mill.


1997 ◽  
Vol 493 ◽  
Author(s):  
S. P. Alpay ◽  
A. S. Prakash ◽  
S. Aggarwal ◽  
R. Ramesh ◽  
A. L. Roytburd ◽  
...  

ABSTRACTA PbTiO3(001) film grown on MgO(001) by pulsed laser deposition is examined as an example to demonstrate the applications of the domain stability map for epitaxial perovskite films which shows regions of stable domains and fractions of domains in a polydomain structure. X-ray diffraction studies indicate that the film has a …c/a/c/a… domain structure in a temperature range of °C to 400°C with the fraction of c-domains decreasing with increasing temperature. These experimental results are in excellent agreement with theoretical predictions based on the stability map.


2014 ◽  
Vol 975 ◽  
pp. 207-212
Author(s):  
Dayse I. dos Santos ◽  
Olayr Modesto Jr. ◽  
Luis Vicente A. Scalvi ◽  
Americo S. Tabata

Metal oxide nanocomposites were prepared by two different routes: polyol and sol-gel. Characterization by X ray diffraction showed that the first process produces directly a two-phase material, while the sol-gel powder never showed second phase below 600°C. Light spectroscopy of the treated powders indicated similarities for the processed materials. Although the overall material compositions are about the same, different structural characteristics are found for each processing. With the exception of Ti-Zn materials, all the double metal oxide powders showed higher absorbance than either TiO2 powder.


2015 ◽  
Vol 70 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Gerhard Sohr ◽  
Nina Ciaghi ◽  
Klaus Wurst ◽  
Hubert Huppertz

AbstractSingle crystals of the hydrous cadmium borate Cd6B22O39·H2O were obtained through a high-pressure/high-temperature experiment at 4.7 GPa and 1000 °C using a Walker-type multianvil apparatus. CdO and partially hydrolyzed B2O3 were used as starting materials. A single crystal X-ray diffraction study has revealed that the structure of Cd6B22O39·H2O is similar to that of the type M6B22O39·H2O (M=Fe, Co). Layers of corner-sharing BO4 groups are interconnected by BO3 groups to form channels containing the metal cations, which are six- and eight-fold coordinated by oxygen atoms. The compound crystallizes in the space group Pnma (no. 62) [R1=0.0379, wR2=0.0552 (all data)] with the unit cell dimensions a=1837.79(5), b=777.92(2), c=819.08(3) pm, and V=1171.00(6) Å3. The IR and Raman spectra reflect the structural characteristics of Cd6B22O39·H2O.


2003 ◽  
Vol 807 ◽  
Author(s):  
T. Advocat ◽  
F. Jorion ◽  
T. Marcillat ◽  
G. Leturcq ◽  
X. Deschanels ◽  
...  

ABSTRACTZirconolite is a potential inorganic matrix that is currently investigated in France, in the framework of the 1991 radioactive waste management law, with a view to provide durable containment of the trivalent and tetravalent minor actinides like neptunium, curium, americium and small quantities of unrecyclable plutonium separated from other nuclear waste. To confirm the actinide loading capacity of the zirconolite calcium site and to study the physical and chemical stability of this type of ceramic when subjected to alpha self-irradiation, zirconolite ceramic pellets were fabricated with 10 wt% plutonium oxide (isotope 239 or 238). The 55 pellets are dense (> 93.3% of the theoretical density on average) and free of cracks. They are characterized by a grain size of between 10 and 20 micrometers. X-ray diffraction analyses confirmed the presence of the zirconolite 2M crystalline structure.


Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.


2012 ◽  
Vol 727-728 ◽  
pp. 1467-1472
Author(s):  
Carla Dantas da Silva ◽  
Rosa do Carmo de Oliveira Lima ◽  
Julliana Marques Rocha Costa ◽  
Gelmires Araújo Neves ◽  
Heber Carlos Ferreira

This work aims at the development of organoclay from two varieties of bentonite for use in organic media using ionic surfactants, studying the influence of process variables in the organophilization process. We used the following materials: natural bentonite clay from Cubati-PB District, and the ionic quaternary ammonium salt: Praepagen WB® with 45% active matter. The clays were benefited and then turned into sodium form and subsequently into organoclays. The bentonites were characterized by laser diffraction (GA) X-ray fluorescence chemical composition (EDX), thermogravimetric analysis (TGA), thermogravimetry (DTA) and X-ray diffraction (XRD). The organoclays were characterized by (XRD) thermogravimetric analysis (TGA) and thermogravimetry (DTA). The results showed that the clay has potential for application in the organophilization process and that there is influence of process variables.


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