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D. D.l. Chung - One of the best experts on this subject based on the ideXlab platform.
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Graphite Intercalation Compounds
Reference Module in Materials Science and Materials Engineering, 2020Co-Authors: D. D.l. ChungAbstract:Graphite intercalation compounds are a type of graphite compounds. They are interstitial compounds in which the foreign species (the intercalate) is included in the interplanar sites of the graphite crystal. They are classified into ionic compounds (e.g., graphite–lithium and graphite–bromine) and covalent compounds (e.g., graphite oxide). Intercalation can only occur in carbon materials that are strongly graphitic. Thus, carbon fibers that are not graphitic cannot be intercalated. Upon heating, an intercalation compound expands along the c -axis, resulting in exfoliated graphite, which has a cellular structure. Upon compression, exfoliated graphite forms flexible graphite, due to the mechanical interlocking among the worms.
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Intercalate vaporization during the exfoliation of graphite intercalated with bromine
Carbon, 2003Co-Authors: D. D.l. ChungAbstract:Abstract Pressure-volume-temperature measurement during the exfoliation of graphite intercalated with bromine showed that exfoliation involved the vaporization of 1 8 of the intercalate, which formed aggregates of at least 8 monolayers thick on the average. At the point of completion of the vaporization, one vaporized intercalate monolayer was about 400 A thick.
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A theory for the kinetics of intercalation of graphite
Carbon, 2003Co-Authors: S.h.anderson Axdal, D. D.l. ChungAbstract:Abstract A theory, which takes into account the evaporation, transport and condensation of the intercalate outside the graphite and the diffusion and staging inside the graphite, is presented for the kinetics of intercalation of graphite. The theory has been applied to a number of Intercalates (including Br2, ICl, K, Rb, Cs, FeCl3, NiCl2, CuCl2, PdCl2, HNO3, AsF5, and SbF5) at various temperatures. Ratecontrolling reaction steps have been identified for different types of intercalation compounds.
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Exfoliation of intercalated graphite
Carbon, 2003Co-Authors: S.h. Anderson, D. D.l. ChungAbstract:Abstract By X-ray diffraction, exfoliated graphite-Br 2 was found to exhibit the same in-plane superlattice ordering as intercalated graphite prior to exfoliation. This ordering persisted even after heating for 1 hr at 1700°C. By dilatometry, a single exfoliation event was found to consist of multiple expansion spurts, which occurred at ~ 150 and ~ 240°C for the first exfoliation, and ~ 100 and ~ 240°C for subsequent cycles. The amount of expansion was found to increase with decreasing intercalate activity during intercalation. With exfoliation cycles to higher temperatures or longer times, the amount of residual expansion after the collapse on cooling increased until no second exfoliation was observed or reheating. Due to intercalate desorption, the amount of expansion for concentrated samples increased with increasing sample width; desorbed samples showed little width dependence. Acoustic emission was observed before appreciable expansion during the first exfoliation cycle; it was not observed during the collapse or subsequent exfoliation cycles. A model of exfoliation involving intercalate islands is proposed.
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A kinetic model of the first intercalation of graphite
Carbon, 2003Co-Authors: K.k. Bardhan, D. D.l. ChungAbstract:Abstract A model of first rapid intercalation is presented to describe the kinetics of intercalation. The model applies to interface-controlled intercalation, as for the intercalation of Br2 and other similar Intercalates. In this model, intercalation proceeds by layer-by-layer nucleation and subsequent in-plane growth; a time gap is assumed between the nucleation of two successive intercalate layers. The model has been applied to analyze the variation of the surface and thickness profiles and mass increase during intercalation. Support of the model by relevant experimental results is discussed.
Thomas J. Pinnavaia - One of the best experts on this subject based on the ideXlab platform.
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thermoset epoxy clay nanocomposites the dual role of α ω diamines as clay surface modifiers and polymer curing agents
Journal of Solid State Chemistry, 2002Co-Authors: Costas S Triantafillidis, Peter C Lebaron, Thomas J. PinnavaiaAbstract:Diprotonated forms of polyoxypropylene diamines of the type α,ω-[NH3CHCH3CH2(OCH2CHCH3)xNH32+ with x=2.6, 5.6, and 33.1, have been intercalated into montmorillonite and fluorohectorite clays and subsequently evaluated for the formation of glassy epoxy–clay nanocomposites. The intercalated onium ions functioned concomitantly as a clay surface modifier, intragallery polymerization catalyst, and curing agent. Depending on the chain length of the diamine, different orientations of the propylene oxide chains were adopted in the clay galleries, resulting in basal spacings from ∼14 A (lateral monolayer, x=2.6) to ∼45 A (folded structure, x=33.1). The initial clay basal spacings were correlated with the formation of intercalated and exfoliated clay–epoxy nanocomposites with improved mechanical properties and high thermal stabilities. In comparison to clay–monoamine Intercalates, the use of diamine Intercalates greatly reduced the plasticizing effect of the alkyl chains on the polymer matrix, resulting in improved mechanical properties while at the same time reducing the cost and time needed for nanocomposite fabrication.
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Thermoset Epoxy–Clay Nanocomposites: The Dual Role of α,ω-Diamines as Clay Surface Modifiers and Polymer Curing Agents
Journal of Solid State Chemistry, 2002Co-Authors: Costas S Triantafillidis, Peter C Lebaron, Thomas J. PinnavaiaAbstract:Diprotonated forms of polyoxypropylene diamines of the type α,ω-[NH3CHCH3CH2(OCH2CHCH3)xNH32+ with x=2.6, 5.6, and 33.1, have been intercalated into montmorillonite and fluorohectorite clays and subsequently evaluated for the formation of glassy epoxy–clay nanocomposites. The intercalated onium ions functioned concomitantly as a clay surface modifier, intragallery polymerization catalyst, and curing agent. Depending on the chain length of the diamine, different orientations of the propylene oxide chains were adopted in the clay galleries, resulting in basal spacings from ∼14 A (lateral monolayer, x=2.6) to ∼45 A (folded structure, x=33.1). The initial clay basal spacings were correlated with the formation of intercalated and exfoliated clay–epoxy nanocomposites with improved mechanical properties and high thermal stabilities. In comparison to clay–monoamine Intercalates, the use of diamine Intercalates greatly reduced the plasticizing effect of the alkyl chains on the polymer matrix, resulting in improved mechanical properties while at the same time reducing the cost and time needed for nanocomposite fabrication.
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polymer clay nanocomposites
2000Co-Authors: Thomas J. Pinnavaia, Gary W BeallAbstract:Contributors. Series Preface. Preface. Polymer-clay Intercalates. Layered Silicate-Polymer Intercalation Compounds. Electroactive Polymers Intercalated in Clays and Related Solids. Polymer-Clay Nanocomposites Derived from Polymer-Silicate Gels. Polymerization of Organic Monomers and Biomolecules on Hectorite. Nanocomposite Synthesis and Properties. Polymer-Clay Nanocomposites. In Situ Polymerization Route to Nylon 6-Clay Nanocomposites. Epoxy-Clay Nanocomposites. Polypropylene-Clay Nanocomposites. Polyethylene Terephthalate-Clay Nanocomposites. Special Properties and Applications. Polymer-Layered Silicate Nanocomposites with Conventional Flame Retardants. Nanocomposite Technology for Enhancing the Gas Barrier of Polyethylene Terephthalate. Structure and Rheology. Structural Characterization of Polymer-Layered Silicate Nanocomposites. New Conceptual Model for Interpreting Nanocomposite Behavior. Modeling the Phase Behavior of Polymer-Clay Nanocomposites. Rheological Properties of Polymer-Layered Silicate Nanocomposites. Index.
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hybrid organic inorganic nanocomposites exfoliation of magadiite nanolayers in an elastomeric epoxy polymer
Chemistry of Materials, 1998Co-Authors: Zhen Wang And, Thomas J. PinnavaiaAbstract:A newly developed class of paraffin-like organomagadiite Intercalates, interlayered by primary, secondary, tertiary, and quaternary onium ions, has been used to form elastomeric polymer-layered silicate nanocomposites by in situ polymerization during the thermoset process. Depending on the nature of the onium ions, intercalated or exfoliated magadiite nanocomposites were obtained. The exfoliated nanocomposites were typically disordered, but a new type of exfoliated structure also was observed in which the nanolayers were regularly spaced over long distances (e.g., ∼80 A Bragg spacings). The tensile properties of the polymer matrix were improved greatly by the reinforcement effect of the silicate nanolayers. Exfoliated silicate nanolayers were more effective than intercalated assemblies of nanolayers in optimizing reinforcement. Interestingly, organomagadiite exfoliation in the rubbery epoxy matrix improves the elongation-at-break while improving tensile strength, which is opposite to the behavior of conve...
Vítězslav Zima - One of the best experts on this subject based on the ideXlab platform.
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Influence of 1,2-alkanediols on the structure of their Intercalates with strontium phenylphosphonate solved by molecular simulation and experimental methods
Journal of Molecular Modeling, 2016Co-Authors: Jan Svoboda, Ludvík Beneš, Vítězslav Zima, Klára Melánová, Miroslav Pospisil, Milan Pšenička, Petr KovařAbstract:Strontium phenylphosphonate Intercalates with 1,2-diols (from 1,2-ethanediol to 1,2-hexanediol) were synthesized and characterized by X-ray diffraction, thermogravimetry, chemical analysis, and molecular simulation methods. Prepared samples exhibit a very good stability at ambient conditions. Structural arrangement calculated by simulation methods suggested formation of cavities surrounded by six benzene rings. Each cavity contained one molecule of diol and one molecule of water for the 1,2-ethanediol to 1,2-butanediol Intercalates. In the case of 1,2-pentanediol two types of cavities alternated: one with diol molecules and another one with two water molecules. In the 1,2-hexanediol intercalate the benzene rings created two types of cavities containing one or two diol molecules, respectively, and this conformational variability led to a more disordered arrangement with respect to the models with shorter alkyl chains. Coordination of the oxygen atoms of the diols to the strontium atoms of the host follows the same pattern for all 1,2-diol Intercalates except the 1,2-hexanediol intercalate, where these oxygen atoms can be mutually exchanged at their positions. The calculated basal spacings and structural models are in good agreement with experimental basal spacings obtained from X-ray powder diffraction and with other experimental results.
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Intercalates of strontium phenylphosphonate with alcohols structure analysis by experimental and molecular modeling methods
European Journal of Inorganic Chemistry, 2015Co-Authors: Vítězslav Zima, Jan Svoboda, Ludvík Beneš, Klára Melánová, Miroslav Pospisil, Petr Kovař, Ales RůžickaAbstract:Alcohol intercalated strontium phenylphosphonates were prepared by the addition of alcohols to an aqueous solution of strontium phenylphosphonate (SrPhP). These Intercalates are unstable and de-intercalate spontaneously at ambient conditions. For the complete elucidation of their structure, a combination of a single-crystal X-ray diffraction and molecular modeling was used. The structure of the host layers in methanol (SrPhP·MeOH) and ethanol (SrPhP·EtOH) Intercalates is composed of strontium atoms, which are eight-coordinate by oxygen atoms of the phosphonato groups and of water molecules. The structures of SrPhP·MeOH and SrPhP·EtOH differ in the orientation of the phenyl rings. The alcohol molecules reside in the cavities formed by the phenyl rings and are coordinated to the Sr atoms of the host layer through their oxygen atoms. On the basis of the structure of SrPhP·EtOH, the structures of propanol and butanol Intercalates and of strontium phenylphosphonate dihydrate (SrPhP·2H2O) were modeled. The proposed model of SrPhP·2H2O, which features three kinds of water molecules, elucidates the temperature- and humidity-dependent behavior of the compound.
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Intercalation chemistry of layered vanadyl phosphate: a review
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2012Co-Authors: Ludvík Beneš, Jan Svoboda, Klára Melánová, Vítězslav ZimaAbstract:The intercalation chemistry of layered α_I modification of vanadyl phosphate and vanadyl phosphate dihydrate is reviewed. The focus is on neutral molecular guests and on metal cations used as guest species. The basic condition for the ability of the neutral molecules to be intercalated into vanadyl phosphate is a presence of an electron donor atom in them. The most commonly used guest compounds are those containing oxygen, nitrogen or sulfur as electron donor atoms. Regarding the molecules containing oxygen, various compounds were used as molecular guests starting from water to alcohols, ethers, aldehydes, ketones, carboxylic acids, lactones, and esters. An arrangement of the guest molecules in the interlayer space is discussed in connection with the data obtained by powder X-ray diffraction, thermogravimetry, IR and Raman spectroscopies, and solid-state NMR. In some cases, the local structure was suggested on the basis of quantum chemical calculations. Besides of those O-donor guests, also N-donor guests such as amines, nitriles and nitrogenous heterocycles and S-donor guests such as tetrathiafulvalene were intercalated into VOPO_4. Also Intercalates of complexes like ferrocene were prepared. Intercalation of cations is accompanied by a reduction of vanadium(V) to vanadium(IV). In this kind of intercalation reactions, an iodide of the intercalated cation is often used as it serves both as a mild reduction agent and as a source of the intercalated species. Intercalates of alkali metals, hydronium and ammonium were prepared and characterized. In the case of lithium and sodium Intercalates, a staging phenomenon was observed. These redox intercalated vanadyl phosphates undergo ion exchange reactions which are discussed from the point of the nature of cations involved in the exchange. Vanadyl phosphates in which a part of vanadium atom is replaced by other metals are also briefly reviewed.
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Intercalation behavior of calcium phenylphosphonate dihydrate CaC_6H_5PO_3·2H_2O
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2010Co-Authors: Ludvík Beneš, Klára Melánová, J. Svoboda, Vítězslav ZimaAbstract:Intercalates of calcium phenylphosphonate dihydrate with 1-alkylamines (C_2–C_10), 1-alkanols (C_3–C_10), 1,ω-amino alcohols (C_2–C_5), pyridine, morpholine, piperazine, aniline and 1-naphthylamine were prepared and characterized by powder X-ray diffraction and thermogravimetric analysis. The Intercalates of alkanols and alkylamines are unstable at ambient conditions and the guest molecules are tilted to the host layers at an angle of 40°. The amino alcohol Intercalates are stable and their basal spacings are very similar for all amino alcohols used and, in the case of ethanolamine and propanolamine, they contain co-intercalated water. Also arylamines and nitrogenous heterocycles form stable compounds. The general formula of these Intercalates is CaC_6H_5PO_3· x H_2O· y (guest) and their basal spacings are from 15.39 to 15.78 Å.
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Intercalation of aminonaphthalenes into α-zirconium hydrogenphosphate
Journal of Physics and Chemistry of Solids, 2007Co-Authors: Ludvík Beneš, Jan Svoboda, Vítězslav Zima, Klára Melánová, Miloslav KinclAbstract:Abstract Intercalates of 1- and 2-aminonaphthalene (1-AN and 2-AN), 1,5- and 1,8-diaminonaphthalene (1,8-DAN) and 2-aminoanthracene (2-AA) into α -Zr(HPO 4 ) 2 ·H 2 O were prepared and characterized by powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. As follows from IR, molecules of aminonaphthalenes are protonated in the interlayer space. 1,5-diaminonaphthalene (1,5-DAN) molecules are arranged in a monomolecular way in the intercalate. The other guest molecules form partially interdigitated bilayers in the interlayer space.
Christian Detellier - One of the best experts on this subject based on the ideXlab platform.
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Intercalation of cyclic imides in kaolinite
Journal of Colloid and Interface Science, 2008Co-Authors: Tamer A. Elbokl, Christian DetellierAbstract:The intercalation of two cyclic imides, succinimide and glutarimide, in the interlayer spaces of kaolinite was obtained from a "soft guest-displacement method" by displacing previously intercalated guest molecules. The dimethyl sulfoxide (DMSO)-kaolinite preintercalate was particularly efficient for that purpose. The intercalation exchange was done from a concentrated aqueous solution of the cyclic imides, at ambient temperature, in a relatively short time. Complete displacement of DMSO by the cyclic imides was confirmed by the results of several independent characterizations, including XRD, TG/DTA, FTIR, and 13C MAS NMR analyses including dipolar dephasing experiments. The imide Intercalates are two dimensionally constrained in the kaolinite interlayer spaces, and are structurally organized in a flattened configuration with their cycle roughly parallel to the ab plane of the kaolinite layers. Elemental analysis gives the following compositions: Al2Si2O5(OH)4ṡ(C4H5NO2)0.65 and Al2Si2O5(OH)4ṡ(C5H7NO2)0.49, respectively for succinimide and glutarimide. The results of the TG/DTA analyses showed enhanced thermal stabilities of the imide Intercalates compared with the starting materials. The intercalation process from the aqueous solution is reversible: in prolonged contact with water, the imide molecules are released, resulting in the rebuilding of the kaolinite structure. These results demonstrate the potential use of kaolinite as a slow-releasing agent for molecules structurally related to the cyclic imides of this study. © 2008 Elsevier Inc. All rights reserved.
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intercalation and interlamellar grafting of polyols in layered aluminosilicates d sorbitol and adonitol derivatives of kaolinite
Journal of Materials Chemistry, 2003Co-Authors: Kerstin B Brandt, Tamer A. Elbokl, Christian DetellierAbstract:This paper reports the intercalation of alditols into the interlamellar spaces of kaolinite. The alditols were adonitol, a meso compound, and D-sorbitol. The grafting of hydroxy groups onto the aluminol internal surfaces of kaolinite followed the intercalation. The polyols were intercalated into kaolinite by displacing dimethyl sulfoxide (DMSO) from the DMSO–kaolinite intercalate (Kao–DMSO). This was done directly from the alditol melt at temperatures just above the melting point of the respective polyols. The intercalated polyols are arranged in a flattened monolayer arrangement, such that the interlayer expansion was 3.1 A (adonitol) and 4.6 A (D-sorbitol). Infrared spectroscopy showed that heating the intercalated materials at 200 °C for 1 h resulted in the grafting of the alditols on the inner aluminol surface of kaolinite. 13C CP and DD/MAS NMR indicated the complete replacement of the DMSO molecules by the alditol guests and that the alditols were rigidly constrained in the interlamellar spaces of kaolinite. The intercalation of adonitol was monitored with time. The reaction proceeds via a partial collapse of the Kao–DMSO intercalate before the intercalation of the adonitol.
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aluminosilicate nanocomposite materials poly ethylene glycol kaolinite Intercalates
Chemistry of Materials, 1996Co-Authors: James J Tunney, Christian DetellierAbstract:This paper reports the first example of the direct intercalation of an organic polymer into the interlamellar spaces of kaolinite. Poly(ethylene glycols) (PEG 3400 and PEG 1000) were intercalated into kaolinite by displacing dimethyl sulfoxide (DMSO) from the DMSO−kaolinite intercalate (Kao−DMSO). This was done directly from the polymer melt at temperatures between 150 and 200 °C. XRD showed that the intercalated oxyethylene units were arranged in flattened monolayer arrangements, such that the interlayer expansion was 4.0 A. Infrared analysis of Kao−PEG 3400 supported the assignment of a trans conformation to at least a portion of the (O−CH2CH2−O) groups of the PEG polymer while 13C CP and DD/MAS NMR indicated that the polymer was intercalated intact and was more constrained in the interlamellar spaces of kaolinite than it was in its bulk form. TGA/DSC analysis revealed that the complete decomposition of the organic component of the oxyethylene-based organokaolinites did not occur until greater than 1000...
Costas S Triantafillidis - One of the best experts on this subject based on the ideXlab platform.
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thermoset epoxy clay nanocomposites the dual role of α ω diamines as clay surface modifiers and polymer curing agents
Journal of Solid State Chemistry, 2002Co-Authors: Costas S Triantafillidis, Peter C Lebaron, Thomas J. PinnavaiaAbstract:Diprotonated forms of polyoxypropylene diamines of the type α,ω-[NH3CHCH3CH2(OCH2CHCH3)xNH32+ with x=2.6, 5.6, and 33.1, have been intercalated into montmorillonite and fluorohectorite clays and subsequently evaluated for the formation of glassy epoxy–clay nanocomposites. The intercalated onium ions functioned concomitantly as a clay surface modifier, intragallery polymerization catalyst, and curing agent. Depending on the chain length of the diamine, different orientations of the propylene oxide chains were adopted in the clay galleries, resulting in basal spacings from ∼14 A (lateral monolayer, x=2.6) to ∼45 A (folded structure, x=33.1). The initial clay basal spacings were correlated with the formation of intercalated and exfoliated clay–epoxy nanocomposites with improved mechanical properties and high thermal stabilities. In comparison to clay–monoamine Intercalates, the use of diamine Intercalates greatly reduced the plasticizing effect of the alkyl chains on the polymer matrix, resulting in improved mechanical properties while at the same time reducing the cost and time needed for nanocomposite fabrication.
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Thermoset Epoxy–Clay Nanocomposites: The Dual Role of α,ω-Diamines as Clay Surface Modifiers and Polymer Curing Agents
Journal of Solid State Chemistry, 2002Co-Authors: Costas S Triantafillidis, Peter C Lebaron, Thomas J. PinnavaiaAbstract:Diprotonated forms of polyoxypropylene diamines of the type α,ω-[NH3CHCH3CH2(OCH2CHCH3)xNH32+ with x=2.6, 5.6, and 33.1, have been intercalated into montmorillonite and fluorohectorite clays and subsequently evaluated for the formation of glassy epoxy–clay nanocomposites. The intercalated onium ions functioned concomitantly as a clay surface modifier, intragallery polymerization catalyst, and curing agent. Depending on the chain length of the diamine, different orientations of the propylene oxide chains were adopted in the clay galleries, resulting in basal spacings from ∼14 A (lateral monolayer, x=2.6) to ∼45 A (folded structure, x=33.1). The initial clay basal spacings were correlated with the formation of intercalated and exfoliated clay–epoxy nanocomposites with improved mechanical properties and high thermal stabilities. In comparison to clay–monoamine Intercalates, the use of diamine Intercalates greatly reduced the plasticizing effect of the alkyl chains on the polymer matrix, resulting in improved mechanical properties while at the same time reducing the cost and time needed for nanocomposite fabrication.
