Home About us Contact
|
Home About us Contact | ||
|
|
||
Inorganic Layers (inorganic + layer)
Selected AbstractsEnergy-Absorbing Hybrid Composites Based on Alternate Carbon-Nanotube and Inorganic LayersADVANCED MATERIALS, Issue 28 2009Qiang Zhang Hybrid materials with aligned carbon nanotubes intercalating naturally layered compounds (see upper figures) are fabricated using general metal-ion intercalation and in situ growth. As indicated by SEM images (lower figures), they exhibit periodic and hierarchical structures. The ability to control their composition resulted in some samples possessing excellent mechanical properties, such as high energy absorption during compression. [source] Inorganic Layers on Polymeric Films , Influence of Defects and Morphology on Barrier PropertiesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2003M. Hanika Abstract Flexible polymeric films are not only widely used in conventional packaging as substitute for glass and aluminum foil packaging but are also proposed as encapsulation for novel products, like flexible solar cells or organic light-emitting devices. The two essential properties of the polymeric packaging are flexibility and good permeation barrier properties against gases and vapors. This article deals with vacuum web coating as a common way of increasing barrier properties of polymeric films and the problems related to this procedure. Defects caused by particles and surface imperfections are found to dominate the permeation rate for such coated polymeric films. Atomic force microscopy, electron and also optical microscopy was used for analysis of the coating layer. Three-dimensional numerical simulations were performed for modeling of the influence of defect size, spacing and film thickness. Results of numerical modeling and of many practical experiments show that the permeability is almost independent of the substrate film thickness when a critical thickness is exceeded. In most cases the defects can be treated as independent of each other. The gas permeability of vacuum web-coated polymeric films can be quantitatively predicted by a simple formula. For gases, like oxygen, it is shown that a statistic analysis of the defect sizes by optical microscopy is sufficient. For water vapor transmission, however, the structure of the coating layer itself has also to be taken into account. [source] Hydrothermal Synthesis and Characterization of Two New Three-Dimensional Open-Framework Gallophosphates JGP-n (n: 8,9) Constructed from Inorganic Layers and HPO4 Tetrahedra.CHEMINFORM, Issue 15 2005Yulin Yang Abstract For Abstract see ChemInform Abstract in Full Text. [source] Pillared Layered Metal Phosphonates Showing Field-Induced Magnetic TransitionsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2010Peng-Fei Wang Abstract The first examples of metal phosphonates based on 6-phosphononicotinic acid (pnaH3), namely, M3(pna)2(H2O)2 {1: M = CuII, 2: M = CoII} are reported. Both possess pillared layered structures. Within the inorganic layer, chains made up of dimers of edge-sharing {M2O6} octahedra and {M1O6} octahedra through O(1W), O,P,O, and O,C,O units are interconnected by {PO3C} tetrahedra. The pyridyl groups of pna3, serve as the pillars. An antiferromagnetic ground state is found for each compound. When the external field reaches critical points at low temperature, compound 1 features a spin flop transition, whereas 2 shows metamagnetic behavior. [source] Syntheses, Crystal Structures, and Characterizations of a Series of New Layered Lanthanide Carboxylate-PhosphonatesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2006Si-Fu Tang Abstract Hydrothermal reactions of different lanthanide(III) salts with (H2O3PCH2)2NCH2COOH (H5L1) led to two new layeredlanthanide(III) carboxylate-diphosphonates, namely La(H2L1)(H2O)2·H2O (1) and La(H2L1)(H2O) (2). The structure of compound 1 features a layered architecture in which the nine-coordinate La3+ ions are bridged by phosphonate groups of the ligands. The carboxylate group of the phosphonate ligand remains protonated and is involved in the interlayer hydrogen bonding. Compound 2 features a double layer structure in which the La3+ ion is eight-coordinated and the carboxylate group of the ligand is chelated to a La3+ ion in a bidentate fashion. Hydrothermal reactions of lanthanide(III) salts with 4-HOOC,C6H4,CH2N(CH2PO3H2)2 (H5L2) afforded three new compounds, namely, La(H4L2)(H3L2)(H2O)·2H2O (3), Er(H3L2)(H4L2) (4), and Er(HL3)(H2L3)(H2O) (5) [H2L3 = H2O3PCH2N(CHO)(CH2,C6H4,COOH)]. H2L3 was formed by the in situ oxidation of one P,C bond of the H5L2 ligand. Compound 3 features a (002) lanthanum(III) phosphonate layer in which the seven-coordinate La3+ ions are bridged by diphosphonate moieties of the ligands. The carboxylate group remains protonated and is involved in the interlayer hydrogen bonding. The structure of compound 4 contains a 1D chain along the a axis in which each pair of ErO6 octahedra is bridged by a pair of phosphonate groups. These 1D chains are further interconnected by hydrogen bonds between noncoordinated phosphonate oxygen atoms into a (002) layer with the phenyl carboxylate groups hanging on the interlayer space. The structure of compound 5 is also layered. The interconnection of Er3+ ions by bidentate and tetradentate bridging phosphonate groups resulted in a (002) inorganic layer with the organic groups orientated to the interlayer space. Luminescence properties of compounds 4 and 5 have also been studied.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Highly Efficient p-i-n and Tandem Organic Light-Emitting Devices Using an Air-Stable and Low-Temperature-Evaporable Metal Azide as an n-DopantADVANCED FUNCTIONAL MATERIALS, Issue 11 2010Kyoung Soo Yook Abstract Cesium azide (CsN3) is employed as a novel n-dopant because of its air stability and low deposition temperature. CsN3 is easily co-deposited with the electron transporting materials in an organic molecular beam deposition chamber so that it works well as an n-dopant in the electron transport layer because its evaporation temperature is similar to that of common organic materials. The driving voltage of the p-i-n device with the CsN3 -doped n-type layer and a MoO3 -doped p-type layer is greatly reduced, and this device exhibits a very high power efficiency (57,lm W,1). Additionally, an n-doping mechanism study reveals that CsN3 was decomposed into Cs and N2 during the evaporation. The charge injection mechanism was investigated using transient electroluminescence and capacitance,voltage measurements. A very highly efficient tandem organic light-emitting diodes (OLED; 84,cd A,1) is also created using an n,p junction that is composed of the CsN3 -doped n-type organic layer/MoO3 p-type inorganic layer as the interconnecting unit. This work demonstrates that an air-stable and low-temperature-evaporable inorganic n-dopant can very effectively enhance the device performance in p-i-n and tandem OLEDs, as well as simplify the material handling for the vacuum deposition process. [source] A Delivery System for Self-Healing Inorganic Films,ADVANCED FUNCTIONAL MATERIALS, Issue 22 2008Harvey A. Liu Abstract Multilayer composites that utilize polymeric and brittle inorganic films are essential components for extending the lifetimes and exploiting the flexibility of many electronic devices. However, crack formation within the brittle inorganic layers that arise from defects as well as the flexing of these multilayer composite materials allows the influx of atmospheric water, a major source of device degradation. Thus, a composite material that can initiate self-healing upon the influx of environmental water through defects or stress-induced cracks would find potential applications in multilayer composite materials for permeation barriers. In the present study, the reactive metal oxide precursor TiCl4 is encapsulated within the pores of a degradable polymer, poly(lactic acid) (PLA). Electrospun PLA fibers are found to be reactive to atmospheric water leading to the hydrolysis of the degradable polymer shell and subsequent release of the reactive metal oxide precursor. Release of the reactive TiCl4 from the pores results in hydrolysis of the metal oxide precursor, forming solid titanium oxides at the surface of the fibers. The efficacy of this self-healing delivery system is also demonstrated by the integration of these reactive fibers in the polymer planarization layer, poly(methyl methacrylate), of a multilayer film, upon which an alumina barrier layer is deposited. The introduction of nanocracks in the alumina barrier layer lead to the release of the metal oxide precursor from the pores of the fibers and the formation of titanium dioxide nanoparticles within the crack and upon the thin film surface. In this study the first delivery system that may find utility for the self-healing of multilayer barrier films through the site-specific delivery of metal oxide nanoparticles through smart reactive composite fibers is established. [source] A three-dimensional hybrid framework based on novel [Co4Mo4] bimetallic oxide clusters with 3,5-bis(3-pyridyl)-1,2,4-triazole ligandsACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2009Quan-Guo Zhai In the title organic,inorganic hybrid complex, poly[[[,-3,5-bis(3-pyridyl)-1,2,4-triazole]tri-,3 -oxido-tetra-,2 -oxido-oxidodicobalt(II)dimolybdenum(VI)] monohydrate], {[Co2Mo2O8(C12H9N5)]·H2O}n, the asymmetric unit is composed of two CoII centers, two [MoVIO4] tetrahedral units, one neutral 3,5-bis(3-pyridyl)-1,2,4-triazole (BPT) ligand and one solvent water molecule. The cobalt centers both exhibit octahedral [CoO5N] coordination environments. Four CoII and four MoVI centers are linked by ,2 -oxide and/or ,3 -oxide bridges to give an unprecedented bimetallic octanuclear [Co4Mo4O22N4] cluster, which can be regarded as the first example of a metal-substituted octamolybdate and exhibits a structure different from those of the eight octamolybdate isomers reported to date. The bimetallic oxide clusters are linked to each other through corner-sharing to give two-dimensional inorganic layers, which are further bridged by trans -BPT ligands to generate a three-dimensional organic,inorganic hybrid architecture with six-connected distorted ,-Po topology. [source] | |||||||||||||