scholarly journals Intrinsic Effect of Pyridine-N-Position on Structural Properties of Cu-Based Low-Dimensional Coordination Frameworks

2020 ◽  
Vol 21 (17) ◽  
pp. 6171
Author(s):  
Anna Walczak ◽  
Gracjan Kurpik ◽  
Artur R. Stefankiewicz
Keyword(s):  
Physicochemical Characterization ◽  
Pyridine Nitrogen ◽  
Nitrogen Donor ◽  
Metal Organic ◽  
Low Dimensional ◽  
Polymeric Assemblies ◽  
Organic Assemblies ◽  
Intrinsic Effect ◽  
Supramolecular Aggregates

Metal-organic assemblies have received significant attention for catalytic and other applications, including gas and energy storage, due to their porosity and thermal/chemical stability. Here, we report the synthesis and physicochemical characterization of three metallosupramolecular assemblies consisting of isomeric ambidentate pyridyl-β-diketonate ligands L1–L3 and Cu(II) metal ions. It has been demonstrated that the topology and dimensionality of generated supramolecular aggregates depend on the location of the pyridine nitrogen donor atom in L1–L3. This is seen in characterization of two distinct 2D polymeric assemblies, i.e., [Cu(L1)2]n and [Cu(L2)2]n, in which both β-diketonate and pyridine groups are coordinated to the Cu(II) center, as well as in characterization of the mononuclear 1D complex Cu(L3)2, in which the central atom is bound only by two β-diketonate units.

Growth and Characterization of MOCVD Grown Gallium Phosphide Nanostructures on Silicon Substrates

2013 ◽  
Vol 716 ◽  
pp. 281-285 ◽  
Author(s):  
Sisir Chowdhury ◽  
Nripendra N. Halder ◽  
P. Banerji
Keyword(s):  
Band Gap ◽  
Gallium Phosphide ◽  
Chemical Vapor ◽  
Blue Shift ◽  
Organic Chemical ◽  
Silicon Substrates ◽  
Si Substrates ◽  
Metal Organic ◽  
Low Dimensional

Gallium Phosphide (GaP) nanostructures were grown on p-Si substrates by Metal Organic Chemical Vapor Deposition (MOCVD) to study the structure of low dimensional IIIV semiconductor on Si substrates. It is found that at a temperature of 540 °C, nanostructures with diameter 4080 nm and height 515 nm were obtained. The density of the nanostructures was found to be 1014 m-2. The UV-Vis-NIR spectra showed a blue shift of band gap. Photoluminescence measurements also confirmed the band gap enhancement.

scholarly journals Metal-Organic Frameworks Characterization via Inverse Pulse Gas Chromatography

2021 ◽  
Vol 11 (21) ◽  
pp. 10243
Author(s):  
Kareem Yusuf ◽  
Osama Shekhah ◽  
Zeid ALOthman ◽  
Mohamed Eddaoudi
Keyword(s):  
Gas Chromatography ◽  
Inverse Gas Chromatography ◽  
Metal Organic Frameworks ◽  
Physicochemical Characterization ◽  
Structure Design ◽  
Fundamental Theory ◽  
Complete Control ◽  
Metal Organic ◽  
Common Application

The desire to customize the properties of a material through complete control over both its chemical and architectural structure has created a constant and persistent need for efficient and convenient characterization techniques. Inverse gas chromatography (IGC) is considered a useful characterization method for probing the material’s surface properties, like its enthalpies of adsorption, which are the key stimulus components for their adsorption performance. Here, we conclusively review the significance of a less common application of the IGC technique for the physicochemical characterization of metal-organic frameworks (MOFs), which are an innovative subclass of porous materials with matchless properties in terms of structure design and properties. This review focuses on the fundamental theory and instrumentation of IGC as well as its most significant applications in the field of MOF characterization to shed more light on this unique technique.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

Optimization and Physicochemical Characterization of Chitosan and Chitosan Nanoparticles Extracted from the Crayfish Procambarus clarkii Wastes

2019 ◽  
Vol 38 (2) ◽  
pp. 385 ◽  
Author(s):  
Marwa M. El-Naggar ◽  
Wael S. I. Abou-Elmagd ◽  
Ashraf Suloma ◽  
Hamza A. El-Shabaka ◽  
Magdy T. Khalil ◽  
...  
Keyword(s):  
Procambarus Clarkii ◽  
Chitosan Nanoparticles ◽  
Physicochemical Characterization

Physicochemical Characterization of Solid Dispersions of Cefdinir with PVP K-30 and PEG 4000

2010 ◽  
Vol 3 (2) ◽  
pp. 948-956
Author(s):  
Kumar P ◽  
S Kumar ◽  
A Kumar ◽  
M Chander
Keyword(s):  
Solid Dispersions ◽  
Physicochemical Characterization ◽  
Drug Carriers ◽  
Dissolution Properties ◽  
Rate Of Dissolution ◽  
Peg 4000 ◽  
Release Studies ◽  
Crystalline Nature ◽  
Physical Mixtures

The purpose of this study was to prepare and characterize solid dispersions of the antibacterial agent Cefdinir with PEG 4000 and PVP K-30 with a view to improve its dissolution properties. Investigations of the properties of the dispersions were performed using release studies, X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR). The results obtained showed that the rate of dissolution of Cefdinir was considerably improved when formulated in solid dispersions with PVP K-30 and PEG 4000 as compared with pure drug and physical mixtures. The results from XRD studies showed the transition of crystalline nature of drug to amorphous form, while FTIR studies demonstrated the absence of drug-carriers interaction.

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