scholarly journals The Amounts of Water Adsorbed to the Surface of Clay Minerals at the Plastic Limit

2017 ◽  
Vol 64 (3-4) ◽  
pp. 155-162
Author(s):  
Aleksandra Gorączko ◽  
Andrzej Olchawa
Keyword(s):  
Surface Area ◽  
External Surface ◽  
Solid Phase ◽  
Water System ◽  
Basal Spacing ◽  
Plastic Limit ◽  
X Ray Diffraction ◽  
External Surface Area ◽  
X Ray ◽  
Water Layers

AbstractThe paper presents results of a study on the amount of water associated with the solid phase of the clay water system at the plastic limit. Two model monomineral clays, namely kaolinite, and montmorillonite, were used in the study. The latter was obtained by gravitational sedimentation of Na-bentonite (Wyoming).The calculated mean number of water molecule layers on the external surface of montmorillonite was 14.4, and water in interlayer spaces constituted 0.3 of the water mass at the plastic limit.The number of water layers on the external surface of kaolinite particles was 63, which was related to the higher density of the surface electrical charge of kaolinite compared to that of montmorillonite.The calculations were made on the basis of the external surface area of clays and the basal spacing at the plastic limit measured by an X-ray diffraction test. The external surface area of clays was estimated by measuring sorption at a relative humidity p/p0 = 0.5.

Changes in kaolinite, vermiculite, and smectite clays after adsorption by hydroxy-chromium species

Soil Research ◽  
1998 ◽  
Vol 36 (3) ◽  
pp. 423 ◽  
Author(s):  
Cristina Volzone
Keyword(s):  
Surface Area ◽  
Nitrate Solution ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
Octahedral Sheet ◽  
Chromium Species ◽  
X Ray ◽  
Micropore Surface Area ◽  
Smectite Clays ◽  
Adsorption Desorption

Kaolinite, vermiculite, and montmorillonites were treated with solutions containing hydroxy-chromium (OH-Cr) species. The OH-Cr solution was prepared by adding 0·2 М NaOH to 0·1 М chromium nitrate solution and allowing the solution to stand at 60°C for 1 day. The samples were characterised by chemical analyses, N2 adsorption-desorption isotherms, and X-ray diffraction. The textural and structural behaviours of kaolinite, vermiculite, and the montmorillonites were analysed in the original samples and after treatment with the polymeric OH-Cr species. The montmorillonites showed higher retention of chromium (19·20%), higher basal spacing (2·06 nm), and higher micropore surface area (276 m2/g) than the vermiculite (3·70%, 1·49 nm, 13 m2/g) and kaolinite (1·15%, 0·73 nm, ~1 m2/g) clays after treatment with the OH-Cr species. In contrast, the external surface area increased from 6 to 9 m2/g for kaolinite and from 18 to 24 m2/g for vermiculite, and decreased from 7 to 4 m2/g for montmorillonite after treatment with the OH-Cr solution. The residual chromium, basal spacing, and texture of the clays after treatment with the OH-Cr species were primarily related to the magnitude of the negative charge originating from the octahedral sheet.

scholarly journals Facile Synthesis of Mn0.68Bi0.32OCl Mix-Crystals And Its Supercapacitive Behavior

2021 ◽  
Author(s):  
Y.Z. Song ◽  
B.X. Qi ◽  
M.T. Li ◽  
J.M. Xie
Keyword(s):  
Surface Area ◽  
Solid Phase ◽  
Life Time ◽  
Molar Ratio ◽  
Phase Method ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Solid Phase Method

Abstract Mn0.68Bi0.32OCl mix-crystals for supercapacitor were successfully synthesized via a facile solid-phase method using Bi(NO3)3 and MnCl2 with molar ratio of 1:1 as precursors. The Mn0.68Bi0.32OCl mix-crystals were characterized by scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurements and thermogravimetry and differential scanning calorimetry, respectively. Cyclic voltammetry and galvanostatic charge/discharge technique were performed for the Mn0.68Bi0.32OCl mix-crystals in 1 M Na2SO4 aqueous solutions; the specific capacitance of Mn0.68Bi0.32OCl was about 203 F.g-1 at the current density of 3 A. g-1 with a long life time, owing to the high power density of Mn0.68Bi0.32OCl mix-crystals and the higher surface area, good conductivity, and high stability of the Mn0.68Bi0.32OCl mix-crystals.

Chrom/Nanocomposite ZrO2- Pillared Bentonite Catalyst for Castor Oil (Ricinus communis) Hydrocracking

2019 ◽  
Vol 27 ◽  
pp. 31-37
Author(s):  
Karna Wijaya ◽  
Akhmad Syoufian ◽  
Ade Fitroturokhmah ◽  
Wega Trisunaryanti ◽  
Dita Adi Saputra ◽  
...  
Keyword(s):  
Surface Area ◽  
Castor Oil ◽  
Ricinus Communis ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
Adsorption Method ◽  
Ammonia Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
Ir Transmission

It has been carried out preparation of Chrom/Nanocomposite ZrO2-Pillared Bentonite catalyst with varying the amount of impregnating precursor at 0 to 3% (w/w). Material characterization of catalyst was carried out using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Infrared Spectroscopy (IR), Transmission Electron Microscope (TEM), Brunauer, Emmett, Teller (BET) and acidity measurement of ammonia-adsorption method. The results of research showed that pillarization was able to increase the basal spacing, surface area, diameter of pore and total volume of pore in catalyst, however increasing of impregnated Cr metal on bentonite caused the decreasing of basal spacing and surface area of catalyst but it would also caused the increasing amount of acid site. The experimental results showed that the catalyst could convert the castor oil into a liquid phase of 78.80% (w/w) with a biogasoline content of 32,73% (w/w).

PREPARATION AND CHARACTERIZATION OF TITANIA-PILLARED MONTMORILLONITE

2008 ◽  
Vol 15 (03) ◽  
pp. 329-336 ◽  
Author(s):  
YIMIN ZHANG ◽  
SHAOXIAN SONG ◽  
MIN ZHANG ◽  
BIYANG TUO
Keyword(s):  
Thermal Stability ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Thermal Stability ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pillared Montmorillonite

In this work, a Ti -pillared montmorillonite with high thermal stability has been prepared by using a Na -montmorillonite as the host clay and polyhydroxy-titania ions as the pillaring precursor. The formation of Ti -pillared montmorillonite has been confirmed from the characterizations through X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric–differential scanning calorimeter, and specific surface area analyses. In the preparation of Ti -pillared montmorillonite several parameters, such as the type of solvent in which the synthesis is realized, the ratio of polyhydroxy-titania ions and montmorillonite, the intercalation time, the calcining temperature, and calcining time, were tested to understand their effects on the basal spacing. It was shown that this method could produce a Ti -pillared montmorillonite with the basal spacing of 3.74 nm, specific surface area of 409 m2/g, and mean pore size of 2.94 nm, as well as a high thermal stability up to 900°C.

scholarly journals Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

Wide angle X-ray diffraction study of the solid-phase chlorinated poly(ethylene)

Polymer ◽  
2004 ◽  
Vol 45 (18) ◽  
pp. 6341-6348 ◽  
Author(s):  
S. Stoeva ◽  
A. Popov ◽  
R. Rodriguez
Keyword(s):  
Diffraction Study ◽  
Solid Phase ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene

Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  
Keyword(s):  
Surface Area ◽  
Sulphuric Acid ◽  
Enzyme Immobilization ◽  
Morphological Changes ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Mineral Oxides ◽  
Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

Hydrothermal Treatment of Coprecipitated YSZ Powders

2010 ◽  
Vol 660-661 ◽  
pp. 983-988 ◽  
Author(s):  
Alexander Rodrigo Arakaki ◽  
Walter Kenji Yoshito ◽  
Valter Ussui ◽  
Dolores Ribeiro Ricci Lazar
Keyword(s):  
Surface Area ◽  
Hydrothermal Treatment ◽  
Gas Adsorption ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Immersion Method ◽  
Cubic Symmetry ◽  
X Ray ◽  
Granulometric Analysis ◽  
Symmetry Surface

Zirconia stabilized with 8.5 mol% yttria (YSZ) were synthesized by coprecipitation and resulting gels were hydrothermallly treated at 200°C and 220 PSI for 4, 8 and 16 hours. Products were oven dried at 70°C for 24 hours, isostatically pressed as pellets and sintered at 1500 °C for 1 hour. Powders were characterized for surface area with N2 gas adsorption, X-ray diffraction, laser diffraction granulometric analysis and scanning and transmission electronic microscopy. Density of ceramics was measured by an immersion method based on the Archimedes principle. Results showed that powders dried at 70°C are amorphous and after treatment has tetragonal/cubic symmetry. Surface area of powders presented a significant reduction after hydrothermal treatment. Ceramics prepared from hydrothermally treated powders have higher green density but sintered pellets are less dense when compared to that made with powders calcined at 800°C for 1 hour due to the agglomerate state of powders. Solvothermal treatment is a promising procedure to enhance density.

PREPARATION OF ANTIMONY-PLATINUM SURFACE ALLOY ELECTRODE BY ATOM DIFFUSION IN THE SOLID PHASE

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3999-4004
Author(s):  
HIROSHI MATSUI ◽  
KAZUFUMI WATANABE
Keyword(s):  
Diffraction Pattern ◽  
Low Temperatures ◽  
Solid Phase ◽  
Electrochemical Measurement ◽  
X Ray Diffraction ◽  
Platinum Surface ◽  
X Ray ◽  
Atom Diffusion ◽  
Heat Treated ◽  
Titanium Substrates

Antimony-platinum bilayers were prepared on titanium substrates by the two-step electrodeposition in the usual baths, and then surface alloys were formed by the atom diffusion in the solid phase. The simple antimony layer was little influenced by the substrate in both the measurements of X-ray diffraction and the i - E characteristic in a sulfuric acid solution. Regarding the bilayers, the catalytic activity in hydrogen evolution reaction was very sensitive to the presence of platinum, while the hydrogen adsorbability was quite insensitive. An interaction between antimony and platinum was confirmed by the appearance of a new dissolution wave in the electrochemical measurement and the occurrence of a new diffraction in the X-ray diffraction pattern after the heat-treatment of about 400°C. Although the new diffraction disagreed with any of the reported alloys, clear diffraction pattern of PtSb 2 alloy was observed, when the bilayers were heat-treated at about 600°C for one hour. Considering the penetration depth of X-ray, the alloying of antimony and platinum seems to occur also at low temperatures at least at the top surface.

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