Clay Mineral Nanotubes: Stability, Structure and Properties

Montmorillonite is a natural layered clay mineral having myriad applications due mainly to its remarkable ion exchange, intercalation, and swelling properties. It can act as a good host for several compounds. Two intercalated coordination compounds of Cu(II) and Ni(II) with 2,2′-bipyridyl have been prepared in the interlayer spaces of montmorillonite structure. They are characterized on the basis of elemental analysis, infrared spectroscopy, magnetic studies, and X-ray diffraction. Both compounds show similarity in their structure and properties with the respective normal complexes of similar composition. These compounds show good thermal stability. The present intercalated compounds might be useful for their nitrogen-immobilizing properties and high-temperature applications.

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Thermochemical electronegativities of the elements

Nature Communications ◽

10.1038/s41467-021-22429-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Christian Tantardini ◽

Artem R. Oganov

Keyword(s):

Solid State ◽

Chemical Bonding ◽

Structural Chemistry ◽

Solid State Chemistry ◽

Structure And Properties ◽

Bond Energies ◽

Dimensionless Numbers ◽

Bond Polarity ◽

Stability Structure ◽

Definition Of

AbstractElectronegativity is a key property of the elements. Being useful in rationalizing stability, structure and properties of molecules and solids, it has shaped much of the thinking in the fields of structural chemistry and solid state chemistry and physics. There are many definitions of electronegativity, which can be roughly classified as either spectroscopic (these are defined for isolated atoms) or thermochemical (characterizing bond energies and heats of formation of compounds). The most widely used is the thermochemical Pauling’s scale, where electronegativities have units of eV−1/2. Here we identify drawbacks in the definition of Pauling’s electronegativity scale—and, correcting them, arrive at our thermochemical scale, where electronegativities are dimensionless numbers. Our scale displays intuitively correct trends for the 118 elements and leads to an improved description of chemical bonding (e.g., bond polarity) and thermochemistry.

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New Insights in Stability, Structure and Properties of Porous Materials

10.3390/books978-3-03842-451-2 ◽

2017 ◽

Keyword(s):

Porous Materials ◽

Structure And Properties ◽

Stability Structure

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Thermodynamic stability, structure and properties of Fe-based C+N austenite and martensite

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2003878 ◽

2003 ◽

Vol 112 ◽

pp. 259-262 ◽

Cited By ~ 1

Author(s):

V. G. Gavriljuk ◽

A. I. Tyshchenko ◽

J. Rawers ◽

H. Berns

Keyword(s):

Thermodynamic Stability ◽

Structure And Properties ◽

Stability Structure

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Structure and Properties of Hot-Pressed Clay Mineral/Acrifavine Complex Disk

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.1991.tb06850.x ◽

1991 ◽

Vol 74 (11) ◽

pp. 2824-2830

Author(s):

Asao Oya ◽

Makoto Saito ◽

Sugio Otani ◽

Hirokazu Hanaoka

Keyword(s):

Clay Mineral ◽

Structure And Properties

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High Resolution Replication of Organoclay Surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055126 ◽

1982 ◽

Vol 40 ◽

pp. 576-577

Author(s):

W. W. Barker ◽

W. E. Rigsby ◽

V. J. Hurst ◽

W. J. Humphreys

Keyword(s):

Clay Mineral ◽

Organic Molecule ◽

Organic Molecules ◽

X Ray Diffraction ◽

Xrd Pattern ◽

X Ray ◽

Naturally Occurring ◽

Silicate Layers ◽

Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

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Structure of second phases in TiAl alloys containing Cr and B

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087197 ◽

1991 ◽

Vol 49 ◽

pp. 576-577

Author(s):

Ernest L. Hall ◽

Shyh-Chin Huang

Keyword(s):

Grain Size ◽

Second Phase ◽

Structure And Properties ◽

Tial Alloys ◽

Second Phases ◽

Interstitial Elements

Addition of interstitial elements to γ-TiAl alloys is currently being explored as a method for improving the properties of these alloys. Previous work in which a number of interstitial elements were studied showed that boron was particularly effective in refining the grain size in castings, and led to enhanced strength while maintaining reasonable ductility. Other investigators have shown that B in γ-TiAl alloys tends to promote the formation of TiB2 as a second phase. In this study, the microstructure of Bcontaining TiAl alloys was examined in detail in order to describe the mechanism by which B alters the structure and properties of these alloys.

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Relationships between hierarchical structure and properties in macromolecular systems

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126950 ◽

1987 ◽

Vol 45 ◽

pp. 440-443

Author(s):

E. Baer

Keyword(s):

Uniaxial Tension ◽

Hierarchical Structure ◽

Inorganic Material ◽

Hierarchical Structures ◽

Bone Collagen ◽

Structure And Properties ◽

Connective Tissues ◽

Scale Level ◽

Fibrous Protein ◽

Macromolecular Systems

The most advanced macromolecular materials are found in plants and animals, and certainly the connective tissues in mammals are amongst the most advanced macromolecular composites known to mankind. The efficient use of collagen, a fibrous protein, in the design of both soft and hard connective tissues is worthy of comment. Very crudely, in bone collagen serves as a highly efficient binder for the inorganic hydroxyappatite which stiffens the structure. The interactions between the organic fiber of collagen and the inorganic material seem to occur at the nano (scale) level of organization. Epitatic crystallization of the inorganic phase on the fibers has been reported to give a highly anisotropic, stress responsive, structure. Soft connective tissues also have sophisticated oriented hierarchical structures. The collagen fibers are “glued” together by a highly hydrated gel-like proteoglycan matrix. One of the simplest structures of this type is tendon which functions primarily in uniaxial tension as a reinforced elastomeric cable between muscle and bone.

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