scholarly journals Reduction in Processing Time in Ca3Co4O9+δ Ceramics through Nanoprecursors Produced by an Easily Scalable and Environmentally Friendly Process

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2533
Author(s):  
Hippolyte Amaveda ◽  
Maria A. Madre ◽  
Mario Mora ◽  
Miguel A. Torres ◽  
Andres Sotelo
Keyword(s):  
Processing Time ◽  
Environmentally Friendly ◽  
Milling Process ◽  
Solid State Method ◽  
Grain Sizes ◽  
Attrition Milling ◽  
Environmentally Friendly Process ◽  
Short Time ◽  
Power Factor Improvement ◽  
Sintered Materials

Attrition milling is an easily scalable and environmentally friendly process used to produce Ca3Co4O9+δ nanoprecursors in a relatively short time. Sintered materials produced through the classical solid-state method, involving ball milling, show much larger grain sizes and slightly lower density than those obtained in samples produced from attrition-milled precursors. On the other hand, electrical resistivity has been drastically decreased, accompanied with a slight decrease in the Seebeck coefficient in samples obtained from these attrition-milled precursors. Moreover, the use of an attrition milling process leads to a very important reduction in processing time (around 75%), together with a slight power factor improvement of around 10%, when compared to the classically prepared samples.

scholarly journals Homocoupling of terminal alkynes catalyzed by CuCl under solvent-free conditions

2021 ◽  
pp. 174751982110325
Author(s):  
Yan Xiao ◽  
Jiyu Gao ◽  
Peng Chen ◽  
Guangliang Chen ◽  
Zicheng Li ◽  
...  
Keyword(s):  
Functional Group ◽  
Reaction Times ◽  
Environmentally Friendly ◽  
Solvent Free ◽  
Copper Salt ◽  
Terminal Alkynes ◽  
Mild Conditions ◽  
Solvent Free Conditions ◽  
Environmentally Friendly Process

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.

Acetylation of Alcohols and Amines under Visible Light Irradiation: Diacetyl as an Acylation Reagent and Photosensitizer

2021 ◽  
Author(s):  
Pengcheng Lian ◽  
Ruyi Li ◽  
Xiao Wan ◽  
Zixin Xiang ◽  
Hang Liu ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Functional Group ◽  
Environmentally Friendly ◽  
Light Irradiation ◽  
Environmentally Friendly Process

This work developed an unprecedented strategy for the acetylation of alcohols and amines using diacetyl as both an acylation reagent and photosensitizer. This environmentally friendly process exhibits excellent functional group...

Clay Aerogel Composite Materials

2010 ◽  
Vol 63 ◽  
pp. 147-151 ◽  
Author(s):  
David A. Schiraldi ◽  
Matthew D. Gawryla ◽  
Saeed Alhassan
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Environmentally Friendly ◽  
Porous Ceramics ◽  
Low Density ◽  
Polymer Foams ◽  
Freeze Dried ◽  
Aerogel Composite ◽  
Environmentally Friendly Process

A simple, inexpensive, and environmentally-friendly process for converting mixtures of clays and polymers has been developed. Polymer and clay are combined in water, and the mixtures are freeze dried to produce materials which have bulk densities typically in the range of 0.03 – 0.15 g/cm3. These low density polymer/clay aerogel materials possess good mechanical properties similar to those of traditional polymer foams, can be reinforced with fibers, modified with nanoparticles, biomineralized, or converted into porous ceramics.

A low cost, low energy, environmentally friendly process for producing high-purity boron carbide

2019 ◽  
Vol 45 (3) ◽  
pp. 3101-3110 ◽  
Author(s):  
Shuaibo Gao ◽  
Xin Li ◽  
Shuai Wang ◽  
Pengfei Xing ◽  
Jian kong ◽  
...  
Keyword(s):  
Boron Carbide ◽  
High Purity ◽  
Low Cost ◽  
Environmentally Friendly ◽  
Low Energy ◽  
Environmentally Friendly Process

Environmentally friendly SPPS I. Application of NaOH in 2-MeTHF/methanol for Fmoc removal

2019 ◽  
Vol 21 (4) ◽  
pp. 775-779 ◽  
Author(s):  
Adam Přibylka ◽  
Viktor Krchňák ◽  
Eva Schütznerová
Keyword(s):  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Environmentally Friendly ◽  
Environmentally Friendly Process

Focusing on the step-by-step transformation of the traditional solid-phase peptide synthesis (SPPS) into an environmentally friendly process, we herein report the elimination of environmentally hazardous components (piperidine, DMF and DCM) from this technique.

HIGH THERMAL STABILITY OF MICROWAVE DIELECTRIC PROPERTIES OF CaTi1-x(Nb1/2Fe1/2)xO3 CERAMICS

2011 ◽  
Vol 01 (04) ◽  
pp. 417-427 ◽  
Author(s):  
A. D. S. BRUNO COSTA ◽  
M. C. ROMEU ◽  
R. C. S. COSTA ◽  
T. S. M. FERNANDES ◽  
F. W. DE O. AMARANTE ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Solid Solutions ◽  
Microwave Dielectric Properties ◽  
Titanium Content ◽  
Milling Process ◽  
Solid State Method ◽  
Small Shift ◽  
X Ray ◽  
Microwave Dielectric

This paper presents a study of the structure and microwave properties of [Formula: see text] substituted into the Ti 4+ site of calcium titanate ceramics. The structural and dielectric properties of solid solutions in CaTi 1-x( Nb 1/2 Fe 1/2)x O 3, was done. The microwave dielectric properties of solid solutions in CaTi 1-x( Nb 1/2 Fe 1/2)x O 3, (CNFTOX with x = 0.1 to x = 1) is discussed. The modified CaTiO3 (CTO) ceramics were prepared by a new procedure in the solid-state method. A study of the variations of the ball-milling process was done. The calcinations were done at 900°C for 3 and 5 h respectively, and the sintering at 1100°C, for 3 h. The structural property studies of the ceramics were investigated by X-ray diffraction (XRD) and Raman spectroscopy. The X-ray analysis showed that all samples have an orthorhombic structure. The refinement analysis of all samples were also duly performed and discussed. The nine scattering bands centered at 183, 227, 247, 288, 338, 470, 490 and 805 cm-1 were observed. Several peaks presented a small shift as a function of the x value. All Raman spectra in the studied samples showed a small band at 805 cm-1, which is a function of the x value. The dielectric permittivity and loss at microwave frequencies (MW) were investigated. For both calcination treatments (900°C for 3 and 5 h), the dielectric permittivity decreased with a decrease of the titanium content. Dielectric permittivity values in the range of 20 to 80 were obtained. It was also observed that a higher number of balls in the milling process contribute to the increase of the εr values. The CNFTO has an excellent microwave property at x = 0.6, with a temperature coefficient of resonant frequency (τf) near zero (τf = 2.8 ppm/°C).

A compact and scalable fabrication method for robust thin film composite membranes

2018 ◽  
Vol 20 (8) ◽  
pp. 1887-1898 ◽  
Author(s):  
Ji Hoon Kim ◽  
Marcus Cook ◽  
Sang Hyun Park ◽  
Sun Ju Moon ◽  
Jeong F. Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Process Intensification ◽  
Environmentally Friendly ◽  
Composite Membranes ◽  
Fabrication Method ◽  
Film Composite ◽  
Thin Film Composite ◽  
Membrane Fabrication ◽  
Environmentally Friendly Process ◽  
Wastewater Generation

A compact and scalable membrane fabrication method proposes an environmentally friendly process intensification in terms of efficiently reduced production time, chemical consumption, and wastewater generation, resulting in a robust membrane.

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