Showing papers in "Applied Clay Science in 2006"

TL;DR: Tombacz et al. as mentioned in this paper performed a similar study on 1:1 type kaolinite obtained from Zettlitz kaolin and showed that the pH-dependent charge formation was similar, positive charges in the protonation reaction of (Si-O) Al-OH sites formed only at pHs below ∼ 6-6.5, considered as the point of zero net proton charge (PZNPC) of kaolin particles.

TL;DR: In this paper, the adsorption process was spontaneous and exothermic in nature and followed first order kinetics, and the linearized form of Langmuir and Freundlich equations were fitted to a linearised form of the Freundich equation.

TL;DR: In this article, six separate processes control the swelling of smectites saturated with alkali and alkaline earth cations in aqueous systems and the basic mechanism and forces controlling each of the processes are different.

TL;DR: In this paper, the authors used the natural bentonite clay collected from Ashapura Clay Mines, Gujarat State, India, was utilized as a precursor to produce aluminium-pillared bentonite Clay (Al-PILC) for the removal of cobalt(II) [Co(II)] ions from aqueous solutions.

TL;DR: In this article, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) were used to provide new insights into the interlayer structure and morphology of HDTMA+/montmorillonite organoclays.

TL;DR: In this paper, the effect on ceramic products of firing conditions in the presence of abundant organic matter is assessed by reproducing two ancient firing techniques: pit firing, characterised by a high heating rate and short residence time in a reducing atmosphere; kiln firing, with a low heating rate, and long residence time, in an oxidising atmosphere.

TL;DR: In this paper, the influence of chemical composition to position and intensity of the absorption bands observed in the FTIR spectra of palygorskites has been studied by a detailed comparative study of six samples.

TL;DR: In this article, the efficiency of a series of clay minerals (montmorillonite, illite, muscovite, sepiolite and palygorskite) modified with octadecyltrimetylammonium bromide (ODTMA) in the adsorption of the pesticides penconazole, linuron, alachlor, atrazine and metalaxyl were investigated.

TL;DR: In this article, the anion exchange method was used to obtain a hydrotalcite-like compound [Zn2Al(OH)6]2edta·nH2O(ZnAl-edta) with the aim of uptake Cu2+, Cd2+ and Pb2+ from the aqueous solutions by chelating process between edta and metal cations.

TL;DR: In this paper, a detailed analysis of papers investigating reactions of dyes with clay minerals but also considering the reactions with other inorganic solid materials and templates are analyzed and critically reviewed.

TL;DR: Results from time-depending studies showed that the reduction of the bacterial counts by Cu-MMT increased during 24 h, and the ranking of antibacterial activity of the three Cu- MMT was not affected by pH.

TL;DR: In this article, different kinds of porous ceramic membranes were prepared from a raw tubular support from a Moroccan clay, which was used as support to prepare microfiltration and ultrafiltration membranes which were tested for the filtration of electrolytes and dyes solutions.

TL;DR: In this paper, eight clayey raw materials with a different content of illite up to 70 wt.%, have been considered, and they were added to a mixture composed of albite, feldspar sand and quartz sand, to reproduce that commonly used for the production of porcelain stoneware tiles.

TL;DR: In this paper, X-ray diffraction measurements of the samples reveal that in the course of composite formation, intercalation structures containing the anatase phase of TiO2 were formed.

TL;DR: Several methods for characterizing layer charge of smectites were compared in this paper, and four CEC methods were used, based on ion exchange reactions with solutions of barium chloride, ammonium acetate, methylene blue and a chelate complex of Cu(II).

TL;DR: A series of infiltration tests on a 50/50% bentonite pellets/powder mixture compacted at different dry densities are reported and analyzed in this paper, where a common pattern of swelling pressure development has been found in all the tests, regardless the density of the mixture, the dimensions of the specimen, or the initial fabric, since a similar behaviour has also been found for specimens of compacted powder.

TL;DR: In this article, geological, mineralogical and geochemical studies were carried out on the Mayouom kaolin deposit located within a mylonitic shear zone about 30 km north of Foumban town (western Cameroon), in order to define the ore genesis and its economic interest.

TL;DR: In this article, the FITEQL 3.2 computer program was used to model the Cd(II) adsorption on kaolinite-based clays in the absence and presence of humic acid.

TL;DR: In this paper, an experimental alteration study has been conducted in order to determine the kinetics of alteration of a montmorillonitic bentonite under hyperalkaline conditions (NaOH 0.5 to 0.1 M) in the presence of portlandite.

TL;DR: In this paper, the authors showed that a major part of TiO2 in the pillared clay could be well below 10 nm in size, which is supported by XRD and the average pore size.

TL;DR: In this article, a modified silver-thiourea method is proposed, which uses a chemically more stable exchange solution, eliminating silver sulphide precipitation and substantially lowering excess adsorption, which is abolished by additional washings.

TL;DR: In this article, the results have shown that any of the contaminants is adsorbed according to a multilayer cooperative mechanism, while Cd2+ is not adorbed at all.

TL;DR: In this paper, the adsorption of low polarity pesticides Carbetamide and Metamitron on hydrotalcite [Mg 3 Al(OH) 8 ] 2 CO 3 · n H 2 O and organohydrotal cites with different degree of dodecyl sulphate (DDS) saturation was reported.

TL;DR: In this paper, the dithiocarbamate-anchored polymer/organosmectite composites were prepared for the removal of heavy metal ions (lead, cadmium and chromium) from aqueous media containing different amounts of these ions (50-750 ppm) and at different pH values (2.0-8.0).

TL;DR: In this article, a model is proposed enabling the detection of incorrect cation exchange capacity (CEC) and exchangeable cation values, which can be used to evaluate the accuracy of results.

TL;DR: In this article, the surface acidity of montmorillonite treated by conventional hydrothermal reaction with acids as well as ultrasonic-and microwave-assisted acid digestion was studied using diffuse reflectance FT-IR (DRIFT) spectroscopy of adsorbed pyridine molecules.

TL;DR: In this article, the pozzolanic activity of Tunisian clays is evaluated by compressive strength performed on calcinated clay-calcium hydroxide mini-cylinders.

TL;DR: In this article, various 2.1 type clay minerals were activated by H2SO4 treatment and their solid acidities were evaluated by NH3-temperature programmed desorption (TPD).

TL;DR: Mingguang palygorskite clays, when modified with the silver and copper ion may be useful in removing bacteria from aqueous solution as discussed by the authors, and the antibacterial effect of these modified clays were investigated using Escherichia coli and Staphylococcus aureus as indicators of fecal contamination of water.

TL;DR: Christidis et al. as discussed by the authors examined the influence of layer charge and charge distribution of dioctahedral smectites on the rheological and swelling properties of bentonites.