Properties Of Intercalation Compounds Research Articles

A comparison of molecular structure and de-intercalation kinetics of kaolinite/quaternary ammonium salt and alkylamine intercalation compounds

It has great significance to research the effect of intercalated molecules with the same carbon chain and different functional groups on the properties of intercalation compounds since it can reveal the effect of different functional groups on the properties of intercalated compounds without considering the difference of carbon chains. In this study, the intercalation compounds of kaolinite/dodecyl trimethyl ammonium chloride (Kaol-DTAC) and kaolinite/dodecylamine (Kaol-DA) were studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetry and differential scanning calorimetry (TG-DSC) analysis, and Scanning electron microscope (SEM). Then the de-intercalation kinetics with different heating rates was investigated, and the optimized the mechanism function for de-intercalation process was calculated. The results showed that the basal spacings of Kaol-DTAC and Kaol-DA intercalation compounds are 3.56 and 4.08 nm, respectively. The DTAC molecules are arranged the Kaol surface in a single layer with an angle of 90° while the DA molecules are tilted towards the Kaol surface in bilayer and the inclination angle is 39.9°, which is due to the different structure between these two type molecules. The SEM showed that the ratio, nanoscrolls length to diameter, of Kaol-DA is larger than that of Kaol-DTAC, and for the yield of nanoscrolls, the former is greater than the latter. Moreover, by using KAS and Ozawa methods, the activation energy (E) of Kaol-DTAC and Kaol-DA were obtained and the average values are 102.44 kJ mol−1 and 130.80 kJ mol−1, respectively. Furthermore, The optimal mechanism function for the intercalation compounds of Kaol-DTAC and Kaol-DA are G(α) = -ln(1-α) and G(α) = [(1-α)(−1/3)−1]2, respectively.

層間化合物とその物性 : グラファイト・アルカリ金属層間化合物を中心として

層間化合物とその物性 : グラファイト・アルカリ金属層間化合物を中心として

Structural phase transformations and physical properties of intercalation compounds in the Cr0.5Ti(Se1−x Tex)2 system

The atomic structure and magnetic and electric properties of the Cr0.5TiSe2-Cr0.5TiTe2 system of intercalated phases were studied in detail by gradually replacing selenium by tellurium. It was revealed that this replacement changes the crystalline structure from monoclinic in the initial compounds to hexagonal in the compounds containing various types of chalcogen atoms; this is accompanied by disordering of chromium atoms in the van der Waals gaps. The electrical resistance and magnetic characteristics vary nonmonotonically on replacement of selenium by tellurium, which is associated with a change in the degree of atomic disordering during the transition from Cr0.5TiSe2 to Cr0.5TiTe2.

Synthesis, Functionalization, and Properties of Intercalation Compounds

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis, functionalization, and properties of intercalation compounds

Layered compounds are nanostructured, intrinsically anisotropic materials which often undergo intercalation reactions producing host–guest complexes. In this work examples from the molybdenum disulfide chemistry are used for discussing how the properties of the products may be regulated by appropriate selection of the guests species used for functionalizing the pristine sulfide. Special attention is given to new intercalates based in the intercalation of surfactants, which under special conditions may act as template promoting the conversion of the layered products into micro and nanotubes. The form how this kind of surfactants may be used for obtaining laminar derivatives of cadmium disulfide with the sulfide in a confined state is also described.

Electronic kinetic properties of the high-temperature phase of the intercalation compound AgxTiSe2

The traditional approach to interpretation of the concentration dependences of the properties of intercalation compounds is based on the assumption that the incorporated atoms are bound in the same way to the host lattice, so that the degree of ionization of the intercalant does not depend on its content in the sample. Studies of the phase diagram of AgxTiSe2, however, cast serious doubts on the validity of this approach in this case, since the concentration dependences of the thermodynamic functions of the silver atom system ~such as the entropy S and Gibbs free energy G) calculated for different phases of this compound were found to be quite different. 1 The minimum and the subsequent sharp maximum in the S(x) relation for the Ag1/4TiSe2 phase do not permit associating the entropy of the silver atoms solely with the configurational contribution of the silver ions and require taking into account the electronic term. This term can become appreciable only in the case of a high electronicstate density at the Fermi level. This is consistent with the observation 2 that the carrier electrons in the Ag 1/4TiSe2 phase are localized. The above suggests formation of covalent centers with incorporated silver in the phase in question. The presence of such centers would also account for the fact that the lattice parameter c 0 increases only by 0.18 A from TiSe2 to Ag1/4TiSe2, 1 whereas intercalation of titanium diselenide even by lithium brings about a substantially larger increase of c 0 . 3 At the same time the S(x) relations constructed for the other two phases of AgxTiSe2 are monotonic, 1 which permitted the present authors to suggest, on the basis of an analysis of the silver contents required for the formation of the phases, that phases II and I are, respectively, stages II and I of intercalation of the Ag 1/4TiSe2 compound. AgxTiS2 ~Ref. 4!, a structural analog of AgxTiSe2, was used as a specific example to prove the validity of the model 5 relating intercalation stages to elastic distortions the lattice suffers when the intercalated atoms cause the interlayer distance to increase. Hence stages can appear only if the incorporated atoms forming a stage are fully ionized. Thus phases II and I should not exhibit formation of new covalent bonds and, accordingly, any carrier localization effects. This work deals with a study of the electronic properties of silver-rich phases in the AgxTiSe2 system and is aimed at identifying the nature of chemical bonding of the incorporated atoms with the host lattice.