Mineralogical and physico-chemical properties of four Thai soils with Special Reference to specific surface area (SSA) and zero point of charge (ZPC)

AbstractOpaline mudstone (OM) composed of opal-CT (SiO2·nH2O) has high potential use as a cesium (Cs) adsorbent, due to its high specific surface area (SSA). The objective of this study was to investigate the Cs adsorption capacity of chemically activated OM and the adsorption mechanism based on its physico-chemical properties. We used acid- and base-activation methods for the surface modification of OM. Both acid- and base- activations highly increased the specific surface area (SSA) of OM, however, the base-activation decreased the zeta potential value more (− 16.67 mV), compared to the effects of acid-activation (− 6.60 mV) or non-activation method (− 6.66 mV). Base-activated OM showed higher Cs adsorption capacity (32.14 mg/g) than the others (acid: 12.22 mg/g, non: 15.47 mg/g). These results indicate that base-activation generates pH-dependent negative charge, which facilitates Cs adsorption via electrostatic attraction. In terms of the dynamic atomic behavior, Cs cation adsorbed on the OM mainly exist in the form of inner-sphere complexes (IS) containing minor amounts of water molecules. Consequently, the OM can be used as an effective Cs adsorbent via base-activation as an economical and simple modification method.

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Changes in Zero Point of Charge (ZPC), Specific Surface Area (SSA), and Cation Exchange Capacity (CEC) of kaolinite and montmorillonite, and strongly weathered soils caused by Fe and Al coatings

Soil Science & Plant Nutrition ◽

10.1080/00380768.1990.10415711 ◽

1990 ◽

Vol 36 (1) ◽

pp. 73-81 ◽

Cited By ~ 30

Author(s):

Katsutoshi Sakurai ◽

Atsushi Teshima ◽

Kazutake Kyuma

Keyword(s):

Specific Surface ◽

Cation Exchange ◽

Surface Area ◽

Specific Surface Area ◽

Cation Exchange Capacity ◽

Zero Point ◽

Exchange Capacity ◽

Weathered Soils ◽

Zero Point Of Charge

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SYNTHESIS, STRUCTURE AND PROPERTIES OF ORGANIC GELS BASED ON LARCH BARK TANNINS AND HY-DROLYSIS LIGNIN

chemistry of plant raw material ◽

10.14258/jcprm.2021029635 ◽

2021 ◽

pp. 109-122

Author(s):

Nadezhda Mikhailovna Mikova ◽

Elena Valentinovna Mazurova ◽

Ivan Petrovich Ivanov ◽

Boris Nikolayevich Kuznetsov

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Furfuryl Alcohol ◽

Lignin Content ◽

Sol Gel ◽

Chemical Properties ◽

Hydrolysis Lignin ◽

Physico Chemical ◽

Gel Composition

For the first time, tannin-lignin-formaldehyde and tannin-lignin-furfuryl organic gels were obtained on the basis of larch bark tannins and hydrolysis lignin by sol-gel condensation with formaldehyde and furfuryl alcohol. Their physico-chemical properties were studied by varying the content of lignin (from 5 to 30 wt%) and a fixed mass ratio of polyphenolic substances to the crosslinking reagent (1 : 1.5). With an increase in the lignin content the density of tannin-lignin formaldehyde gels decreases from 0.83 to 0.53 g/ cm3, and that of tannin-lignin-furfuryl gels is from 0.32 to 0.14 g / cm3. According to the FTIR data, the structures of tannin-lignin-formaldehyde and tannin-lignin-furfuryl gels are formed by aromatic fragments cross-linked with methylene and methylene-ether bridges. Scanning electron microscopy shows that the addition of appropriate amounts of lignin to tannins (up to 10 wt% when using formaldehyde and up to 20 wt% when using furfuryl alcohol) promotes the formation of gels with a more developed porous structure. In the case of tannin-lignin-formaldehyde gel, the specific surface area and sorption of methylene blue are 12 m2 / g and 43 mg / g and for tannin-lignin-furfuryl gel – 72 m2 / g and 114.5 mg/g, respectively. It was found that an increase in the lignin content in the gel composition over 20 wt.% is accompanied by the phase localization of lignin (precipitation), which reduces the strength of the resulting gel and reduces its specific surface area.

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Optimization of compositions and technology of production of small-clinker floured cements using the most effective fillers

Bulletin of L N Gumilyov Eurasian National University Technical Science and Technology Series ◽

10.32523/2616-7263-2021-136-3-46-55 ◽

2021 ◽

Vol 136 (3) ◽

pp. 46-55

Author(s):

N.B. Sarsenbayev ◽

◽

B.K. Sarsenbayev ◽

Zh.T. Aimenov ◽

A.Zh. Aimenov ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Crystalline Structure ◽

Specific Surface Area ◽

Chemical Properties ◽

Surface Layers ◽

Fine Powders ◽

Energy Demands ◽

Actual Evaluation ◽

Technology Of Production

Considering the physical chemistry of grinding it is worth quoting the grinding of mineral building material as “the change of physical-chemical properties of finely ground materials can not only be due to the reducing the particle sizes, at mechanical grinding significant changes of the crystalline structure of their surface layers (thickness 15-20 microns) take place, in many cases the technological properties of fine powders are not so much due to dispersability but are namely due to the structure rupture”, at that the energy costs for this are “significantly greater than for the exposal of surfaces with a clean cleavage”. The speed of heterogeneous chemical processes involving fine powders is determined primarily not by the magnitude of their specific surface area, as commonly is believed, but by the decrease of energy of activation as the result of crystalline structure rupture and amorphization. However, both specific surface area and energy demands to achieve are actual evaluation of the effectiveness of any material grinding at a particular unit. The main factor of the production process of cements of low water demand is the grinding, characterized by grindability.

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Influence of the Calcination Temperature on the properties of The Alumina as Catalyst Support for Catalysis

Paliva ◽

10.35933/paliva.2020.04.03 ◽

2020 ◽

pp. 155-161

Author(s):

Tomáš Hlinčík ◽

Veronika Šnajdrová ◽

Veronika Kyselová

Keyword(s):

Specific Surface ◽

Surface Area ◽

Calcination Temperature ◽

Specific Surface Area ◽

Catalyst Support ◽

Chemical Properties ◽

Total Pore Volume ◽

Temperature Range ◽

Calcination Temperatures ◽

Physical And Chemical

Alumina is commonly used in industrial practice as a catalyst support and it is made from boehmite. Depending on the calcination temperature, this mineral is transformed into various crystalline modifications which have different physical and chemical properties. For this reason, the following parameters were determined at different calcination temperatures: length, width, material hardness, specific surface area and total pore volume. The results show that with increasing calcination temperature there have been significant changes which may be important when using the material as a catalyst support, e.g. in the preparation of catalysts or in the design of cat-alytic reactors. The specific surface area, which decreases in the temperature range 450–800 °C, is an important parameter for the preparation of catalysts, so it is appropriate to choose a temperature of 600 °C, when the specific surface area is above 200 m2·g-1. The effect of calcination temperature on the structural transitions of boehmite was also monitored. The results showed that γ-Al2O3 has the most suitable properties as a catalyst sup-port in the temperature range 450–800 °C.

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Investigations of Latvian Illite/Kaolinite Clays Irradiated Under Action of Accelerated Electrons

Materials Science ◽

10.5755/j01.ms.26.1.21446 ◽

2019 ◽

Vol 26 (1) ◽

pp. 99-102

Author(s):

Dāvis CONKA ◽

Līga AVOTINA ◽

Ruta SVINKA ◽

Visvaldis SVINKA ◽

Laris BAUMANE ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Chemical Properties ◽

Absorbed Dose ◽

Free Fraction ◽

Natural Clay ◽

Ir Spectrometry ◽

Accelerated Electrons ◽

Ft Ir

Natural clay is a perspective material for application as sorbents for wastewater treatment as well as for sorption of radionuclides, where the properties of the clays can be changed under influence of ionizing radiation. For application of Latvian illite/kaolinite clays for isotope sorption it is important to characterize the physic-chemical properties of pre-prepared air dried clays. Two fractions of the illite clays were selected. A fraction with grain size 100 μm (SiO2 content 60.9 ± 1.5 wt.%, specific surface area 35 m2/g) and a sand free fraction – 2 μm (SiO2 47.7 ± 1.9 wt.%, specific surface area 38 m2/g). Selected fractions were irradiated with accelerated electrons (5 MeV, ELU-4, Salaspils, absorbed dose up to 500 kGy). Non-irradiated and irradiated clays were analysed with means of Fourier transform infrared (FT-IR) spectrometry.

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Some Physical, Chemical and Mineralogical Properties of Some Canadian Fly Ashes

MRS Proceedings ◽

10.1557/proc-86-113 ◽

1986 ◽

Vol 86 ◽

Cited By ~ 4

Author(s):

R. C. Joshi ◽

B. K. Marsh

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Chemical Properties ◽

Water Soluble ◽

Pozzolanic Activity ◽

Unburned Carbon ◽

Magnetic Fraction ◽

Fly Ashes ◽

Physical And Chemical

ABSTRACTThis paper gives physical and chemical properties of some Canadian fly ashes. Specific surface area, magnetic fraction, water soluble fraction and fraction finer than 45 μm were determined as part of the physical tests. Thermo-gravimetric analyses (TGA) in oxygen and nitrogen were conducted on raw ash samples. The change of pH with time in suspensions of the different ashes in water was also determined. Pozzolanic activity of the ashes with lime for all the ashes was evaluated to measure ash reactivity.The ash activity seems to be related to fineness of the ash measured by the Blaine air permeability method, but not to the fineness measured by nitrogen sorption. Generally the greater the specific surface area, the higher the reactivity of the ash. The correlation was, however, not strong and no other physical or chemical parameter measured in this investigation seems to be related to pozzolanic activity.The results of pH and TGA tests indicated that the ashes differ in many respects from each other. The TGA data suggest that loss on-ignition in many of the ashes is not entirely due to the presence of unburned carbon. Specific surface area determined by various methods seems to provide different values. No characterization parameter was found that was uniquely related to coal type.

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Characterization of halloysite (North East Rif, Morocco): evaluation of its suitability for the ceramics industry

Clay Minerals ◽

10.1180/clm.2018.5 ◽

2018 ◽

Vol 53 (1) ◽

pp. 65-78 ◽

Cited By ~ 6

Author(s):

Abdelilah El Haddar ◽

Elkhadir Gharibi ◽

Ali Azdimousa ◽

Nathalie Fagel ◽

Iz-Eddine El Amrani El Hassani ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Fine Particles ◽

High Plasticity ◽

North East ◽

Physico Chemical ◽

Ceramics Industry ◽

Tubular Crystals

ABSTRACTA halloysite clay from Nador (NE Morocco) was studied to evaluate its suitability in the ceramics industry. A cross-section involving all the Messinian facies was performed in the Melilla Neogene basin, at the foot of the Gourougou volcano, to establish the origin of the halloysite and estimate its reserves. White layers of halloysite and red clays rich in smectite occurring in contact with basal-reef limestone were characterized by mineralogical (XRD, IR), textural (SEM) and physico-chemical analyses (grain-size, Atterberg limits, DTA/TG, XRF and specific surface area). Ceramic properties were evaluated for halloysite fired from 500 to 1100°C to evaluate technical processing for ceramic production.The halloysite clay consists of fine particles with a high plasticity and a large specific surface area. The XRD investigation revealed the presence of 7 Å non-hydrated halloysite along with gibbsite, alunite, K-feldspar and traces of smectite and illite.The presence of halloysite was confirmed from the characteristic IR bands at 3695 and 3618 cm−1and the predominance of tubular crystals observed in the SEM. The chemical analysis revealed high contents linked to the presence of Al-rich phases (gibbsite and alunite). DTA/TG and XRD results of fired clay samples proved the dehydroxylation of halloysite and a rearrangement of metakaolinite to form mullite and spinel at 975°C.The Moroccan halloysite might be suitable for refractory ceramic applications. However, addition of quartz sand might be necessary to avoid crack development during firing and to reduce the plasticity of raw halloysite and minimize shrinkage during sintering.

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Characterization of Samarium Doped Ceria Powders Having High Specific Surface Area Synthesized by Carbon-Assisted Spray Pyrolysis

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.485.137 ◽

2011 ◽

Vol 485 ◽

pp. 137-140 ◽

Cited By ~ 2

Author(s):

Kenichi Myoujin ◽

Hiroki Ichiboshi ◽

Takayuki Kodera ◽

Takashi Ogihara

Keyword(s):

Specific Surface ◽

Relative Density ◽

Spray Pyrolysis ◽

Surface Area ◽

Specific Surface Area ◽

Carbon Sources ◽

Chemical Properties ◽

High Specific Surface Area ◽

Doped Ceria ◽

Physical And Chemical

Spherical samarium doped ceria (Ce0.8Sm0.2O1.9, SDC) powders having high specific surface area (SSA) were successfully synthesized by carbon-assisted spray pyrolysis (CASP). Saccharides, such as monosaccharides and disaccharides, or organic acids were used as carbon sources. The physical and chemical properties of these powders were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Thermo gravimetry-Differential Thermal Analysis (TG-DTA), and BET. Decarbonized powders obtained by this method exhibit spherical morphologies and nano- and submicron-sizes. The SSA of SDC obtained from CASP was more than seven times higher than that obtained from conventional spray pyrolysis (CSP). The SSA of the decarbonized SDC powders obtained by calcination at 900 °C was estimated to be approximately 70 m2/g by using the BET method. The relative density of SDC obtained from CASP was higher than that obtained from CSP. The relative density of the SDC pellet was highest (96 %) when it was sintered at 1400 °C.

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