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The chemistry of clay-organic reactions

01 Jan 1974-
About: The article was published on 1974-01-01 and is currently open access. It has received 1180 citations till now. The article focuses on the topics: Organic reaction.
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Journal ArticleDOI
TL;DR: In this article, a review of polymer-layered silicate nanocomposites is presented, where the polymer chains are sandwiched in between silicate layers and exfoliated layers are more or less uniformly dispersed in the polymer matrix.
Abstract: This review aims at reporting on very recent developments in syntheses, properties and (future) applications of polymer-layered silicate nanocomposites. This new type of materials, based on smectite clays usually rendered hydrophobic through ionic exchange of the sodium interlayer cation with an onium cation, may be prepared via various synthetic routes comprising exfoliation adsorption, in situ intercalative polymerization and melt intercalation. The whole range of polymer matrices is covered, i.e. thermoplastics, thermosets and elastomers. Two types of structure may be obtained, namely intercalated nanocomposites where the polymer chains are sandwiched in between silicate layers and exfoliated nanocomposites where the separated, individual silicate layers are more or less uniformly dispersed in the polymer matrix. This new family of materials exhibits enhanced properties at very low filler level, usually inferior to 5 wt.%, such as increased Young’s modulus and storage modulus, increase in thermal stability and gas barrier properties and good flame retardancy.

5,901 citations

Journal ArticleDOI
22 Apr 1983-Science
TL;DR: The intercalation of polynuclear hydroxy metal cations and metal cluster cations in smectites affords new pillared clay catalysts with pore sizes that can be made larger than those of conventional zeolite catalysts.
Abstract: Recent advances in the intercalation of metal complex cations in smectite clay minerals are leading to the development of new classes of selective heterogeneous catalysts. The selectivity of both metal-catalyzed and proton-catalyzed chemical conversions in clay intercalates can often be regulated by controlling surface chemical equilibria, interlamellar swelling, or reactant pair proximity in the interlayer regions. Also, the intercalation of polynuclear hydroxy metal cations and metal cluster cations in smectites affords new pillared clay catalysts with pore sizes that can be made larger than those of conventional zeolite catalysts.

1,456 citations

Journal ArticleDOI
TL;DR: A review of the development of high performance polyurethane (PU) and its subclass coatings can be found in this paper, where a wide variety of fillers, whiskers and fibers as well as clay and wollastonites with structural modification are described for use in nanocomposite PU coatings.

1,434 citations

Journal ArticleDOI
25 Jun 2003-Langmuir
TL;DR: In this paper, the chemical reduction of graphite oxide (GO) to graphite by either NaBH4 or hydroquinone and also its surface modification with neutral, primary aliphatic amines and amino acids are described.
Abstract: The chemical reduction of graphite oxide (GO) to graphite by either NaBH4 or hydroquinone and also its surface modification with neutral, primary aliphatic amines and amino acids are described. Treatment of GO with NaBH4 leads to turbostatic graphite that upon calcination under an inert atmosphere is transformed to highly ordered graphitic carbon, while the reduction with hydroquinone yields directly crystalline graphite under soft thermal conditions. On account of the surface-exposed epoxy groups present in the GO solid, its surface modification with neutral, primary aliphatic amines or amine-containing molecules (amino acids and aminosiloxanes) takes place easily through the corresponding nucleophilic substitution reactions. In this way, valuable GO derivatives can be obtained, like molecular pillared GO, organically modified GO affording in organic solvents stable organosols or hydrophilic GO affording in water stable hydrosols and possessing direct cation exchange sites. The potential combination of s...

1,168 citations

Journal ArticleDOI
TL;DR: Halloysite clay minerals are ubiquitous in soils and weathered rocks where they occur in a variety of particle shapes and hydration states as discussed by the authors and diversity also characterizes their chemical composition, cation exchange capacity and potassium selectivity.
Abstract: Halloysite clay minerals are ubiquitous in soils and weathered rocks where they occur in a variety of particle shapes and hydration states. Diversity also characterizes their chemical composition, cation exchange capacity and potassium selectivity. This review summarizes the extensive but scattered literature on halloysite, from its natural occurrence, through its crystal structure, chemical and morphological diversity, to its reactivity toward organic compounds, ions and salts, involving the various methods of differentiating halloysite from kaolinite. No unique test seems to be ideal to distinguish these 1:1 clay minerals, especially in soils. The occurrence of 2:1 phyllosilicate contaminants appears, so far, to provide the best explanation for the high charge and potassium selectivity of halloysite. Yet, hydration properties of the mineral probably play a major role in ion sorption. Clear trends seem to relate particle morphology and structural Fe. However, future work is required to understand the possible mechanisms linking chemical, morphological, hydration and charge properties of halloysite.

1,156 citations


Cites background from "The chemistry of clay-organic react..."

  • ...…& Russow, 1963; Camazano & Garcia, 1966; Ledoux & White, 1964; Olejnik et al., 1968, 1970; Range et al., 1969; Alietti, 1970; Carr & Chih, 1971; Theng, 1974; Anton & Rouxhet, 1977; MacEwan & Wilson, 1980; Churchman & Theng, 1984; Churchman et al., 1984; Theng et al., 1984; Churchman, 1990;…...

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  • ...Although polarity is important, no simple relationship is noted between complexing ability and either dielectric constant or dipole moment of the organic molecules, the majority of which intercalate as a flat monolayer (Theng, 1974)....

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