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Showing 1 to 20 of 23 for “"Halloysite"”.
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Pyrochemical changes in Missouri halloysite
<p>"For centuries it has been known that the application of heat to a clay or a clay body produces changes that make it an entirely different substance from the original raw clay. Ever since the earliest civilizations produced crude building brick by baking formed clay bodies in the sun's rays, …
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Halloysite for smart nano-structured materials in sustainable applications
… moieties such as biopolymers. Among clays, Halloysite Nanotubes (HNTs) were deeply investigated due to their peculiar properties: morphology, different chemistry and charges on the internal and external surfaces, high aspect ratio, no toxicity, eco-friendliness and low cost. Hence, this …
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A comparative engineering study of the hydrated (4H2O) and dehydrated (2H2O) forms of halloysite
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1954.
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Bazı halloysit-polimer nanokompozitlerin hazırlanması ve karakterizasyonu
… ortaya çıkmıştır.Abstract A natural sample of halloysite from Balıkesir region was purified with precipitation from water suspension to remove illite and quartz minerals. Methacrylamide (MAA) and pyrrole (Py) monomers were mixed with halloysite in different ratio. The mixtures were polymerized …
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Removal of cationic and anionic dyes from aqueous solution using a clay-based nanocomposite.
… removal from wastewater by calcined magnesite, halloysite nanoclay and calcined magnesite - halloysite nanoclay composite was evaluated. To this end, the study was subdivided to four segments. The first segment of the study focused on evaluating the efficiency of using calcined magnesite to …
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Potassium acetate treatment as a potential means for stabilising extra sensitive, halloysite-rich soils in the Bay of Plenty, New Zealand — A novel approach to an old issue
… reworked rhyolitic tephra deposits dominated by halloysite, known as the Pahoia Tephra, that exhibit a sensitive response. Based on successful tests undertaken in the Northern Hemisphere using potassium chloride salt wells, as well as a pilot study conducted on the same halloysitic materials, the …
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Organic complexes of unrefined and milled kaolin: An infrared spectroscopic study.
… (an effect similar to ageing). A dehydrated halloysite impurity was found which intercalated pyridine. VT XRD showed that deintercalation occurred at c 100 °C. The hydrogen bonding nature of the halloysite-pyridine interactions became less pronounced as milling increased. Pyridine …
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COMPUTATIONAL STUDY OF THE INTERACTION BETWEEN MOLECULES OF TECHNOLOGICAL INTEREST AND MODIFIED NANOTUBULAR CLAYS
Halloysite nanotube (HNT) is an aluminosilicate arranged in a spiral shape, made up of a silicon oxide on the outer and an aluminium hydroxide on the inner surface. These two layers are bonded through oxygen atoms. The different chemical environment of the two surfaces as well as their fine tuning …
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Lime Stabilization of a Virginia Clay Soil
… amount of water with a greater percentage of halloysite minerals. The soil, it was concluded, was poorly crystalline and was found to be midway between montmorillonite and kaolinite group.
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Pedogenesis, weathering processes, and elemental distribution along a soil climosequence in the southern Piedmont
… in the saprolite, and iv) recrystallization of halloysite in the soil/saprolite transition zone. Gibbsite forms from both desilication of kaolinite and by reprecipitation after N a-feldspar dissolution at depth. Halloysite is common to all soils as the product of both feldspar and biotite …
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An assessment of morphological, physical, chemical, and mineralogical properties of soils derived from volcanic deposits in Rwanda
… elevation. Allophane content decreases whereas, halloysite increases with decreasing elevation. Variations in soil properties with elevation reflect differences in clay mineralogical composition. Variations in physical and chemical properties of soils developed from different parent materials may …
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Factors Influencing Biotite Weathering
… weathering mechanism, and (v) precipitation of halloysite in the C horizon at the high elevation site where temperature is lower and a suspected higher leaching intensity occur.
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Mineralogical and ion-exchange leaching study of a Rare Earth Element (REE) bearing ion-adsorption clay deposit
… targeting ion-exchangeable REE on kaolinite, halloysite, REEorganic matter and mineral phase. Ammonium sulphate leach experiments were conducted, varying the ionic strength to determine optimum leaching concentrations. Seawater is easily available at the coastal mine, therefore simulated …
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Biobased And Biodegradable Polymer Nanocomposites
… reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA …
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Removal of Nitrates from Stormwater Using Nanoclays
… unmodified hydrophilic bentonite, unmodified halloysite nanoclay, HCl modified hydrophilic bentonite and HCL modified kaolin) to the control clay, unmodified kaolin, for their ability to adsorb nitrate solution by batch adsorption experiments. The findings determined that the pre-modified …
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Spectroscopic and thermal analysis of clay mineral-organic composites.
… intercalation of the clay minerals Kaolin and Halloysite with Phenylphosphonic Acid (PPA). The intercalation process proceeds via the use of an acetone / water entraining agent and subsequent analysis by Diffuse Reflectance Infrared Fourier transform Spectroscopy (DRIFTS), X-Ray Diffraction …
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Cucurbiturils, tetrahedral capsules, and porous systems: synthesis, functionalization, and applications
… starting from cheap materials such as loofah and halloysite. The composite showed a significantly greater ability to absorb and retain carbon dioxide than non-contaminated materials. This underlines the synergistic effect of the two materials, which also possess a greater adsorption capacity than …
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Influence of low nitrogen gas pressures (< 1.0 MPa) and additives on the nitridation, formation and densification of B and O-SiAlON ceramics produced by reaction bonding and silicothermal reduction
… pressures. These two methods which use Si and/or halloysite clay in place of Si3N4 in the starting mixture represent a cost efficient alternative to the traditional liquid phase sintering typically employed to produce SiAlONs. The influence of the initial compositions and of different additives on …
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The colloid and surface chemistry of allophane
… higher than for clay minerals such as kaolinite, halloysite and montmorillonite and so allophane is one of the few natural colloids which is neutral or positively charged at soil pH’s. The difference between the isoelectric point and the point of zero charge was due to the influence of the two …
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A Study on Supported Metal Catalysts Prepared from Colloidal Precursors
… novel analogues were also obtained, including halloysite, perlite, bioapatite, and macrofibrillar cellulose. In order to understand their physicochemical properties, they were characterised by a combination of Fourier transform infrared microspectroscopy, solid-state ¹H, ¹³C, ²⁷Al, ²⁹Si, and …
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