Effect of particle size and local disorder on specific surface area of layered double hydroxides upon calcination-reconstruction

2018 ◽  
Vol 263 ◽  
pp. 60-64 ◽  
Author(s):  
Bo-Kyung Kim ◽  
Gyeong-Hyeon Gwak ◽  
Tomohiko Okada ◽  
Jae-Min Oh
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layered Double Hydroxides ◽  
Effect Of Particle Size ◽  
Local Disorder ◽  
Double Hydroxides

Tuneable ultra high specific surface area Mg/Al-CO3layered double hydroxides

2015 ◽  
Vol 44 (37) ◽  
pp. 16392-16398 ◽  
Author(s):  
Chunping Chen ◽  
Aunchana Wangriya ◽  
Jean-Charles Buffet ◽  
Dermot O'Hare
Keyword(s):  
Organic Solvent ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layered Double Hydroxides ◽  
High Specific Surface Area ◽  
Double Hydroxides

We report the synthesis of tuneable ultra high specific surface area Aqueous Miscible Organic solvent-Layered Double Hydroxides (AMO-LDHs).

scholarly journals Properties of calcium sulfoaluminate cement-based grouting materials with LiAl-layered double hydroxides slurries

2020 ◽  
Vol 29 ◽  
pp. 2633366X2092652 ◽  
Author(s):  
Haiyan Li ◽  
Xianping Wang ◽  
Xuemao Guan ◽  
Dinghua Zou
Keyword(s):  
Compressive Strength ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layered Double Hydroxides ◽  
Setting Time ◽  
Hydration Products ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Double Hydroxides

In this study, LiAl-layered double hydroxides Lithium aluminum hydrotalcite (LiAl-LDH) with different specific surface area were prepared by the separate nucleation and aging steps (SNAS) method and then were employed to prepare calcium sulfoaluminate cement-based grouting material (CBGM) paste. The influence of LiAl-LDH slurries on fresh and hardened properties of the CBGM paste was investigated in terms of fluidity, stability, setting time, and compressive strength. Additionally, the hydration process and hydration products of the CBGM paste were characterized by hydration heat, X-ray diffraction, differential thermal analysis–thermogravimetry, and Fourier transform infrared analyses. The acquired results illustrated that LiAl-LDH with larger specific surface area led to a faster hydration rate at early age, a lower fluidity, a shorter setting time, and a higher stability. Furthermore, due to the crystal nucleation effect, the addition of LiAl-LDH slurries did not cause a new phase to form but changed the morphology and increased the amount of hydration products, yielding higher compressive strength.

scholarly journals Synthesis of dense porous layered double hydroxides from struvite

2021 ◽  
Vol 23 (4) ◽  
pp. 1616-1620
Author(s):  
W. L. Joyce Kwok ◽  
Hongri Suo ◽  
Chunping Chen ◽  
D. W. Justin Leung ◽  
Jean-Charles Buffet ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layered Double Hydroxides ◽  
Pore Volume ◽  
Wastewater Treatment Plants ◽  
High Specific Surface Area ◽  
Large Pore Volume ◽  
Double Hydroxides

An atom economic synthesis of dense porous layered double hydroxides (SLDHs) using an undesirable waste in wastewater treatment plants (struvite) is reported. The obtained SLDHs show high specific surface area, large pore volume and high density.

scholarly journals Fabrication of β-Ni(OH)2 Particles by Alkaline Etching Layered Double Hydroxides Precursor for Supercapacitor

2022 ◽  
Vol 9 ◽  
Author(s):  
Lumei Chen ◽  
Xiaotong Yang ◽  
Ye Tian ◽  
Yiping Wang ◽  
Xuhui Zhao ◽  
...  
Keyword(s):  
Specific Surface ◽  
Porous Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Layered Double Hydroxides ◽  
Active Material ◽  
Great Influence ◽  
Rate Capability ◽  
Precipitation Reaction ◽  
Double Hydroxides

We report the facile preparation of β-Ni(OH)2 particles by etching a NiAl-layered double hydroxides (NiAl-LDHs) precursor with KOH solution. The amphoteric Al3+ ions in LDHs crystal were selectively dissolved out by KOH solution and LDHs crystals were proposed to be in situ topologically transformed to form β-Ni(OH)2. Alkaline concentration has a great influence on the structure, morphology, specific surface area, and porous structure of the resulting samples. Compared to LDHs precursor and β-Ni(OH)2 prepared by a precipitation reaction, the sample etched in 10 M KOH solution has enhanced specific capacitance (829 F/g at 1 A/g), high rate capability (capacitance retention 57.3% with current density 8 A/g), and good charge/discharge stability. We suggested that the high accessible specific surface area and appropriate porous structure, which is conducive to full contact between active material and electrolyte, can improve the utilization rate of the active material to increase the rate capacity of the 10 M KOH-etched sample.

Physical Properties Variability of Zinc Powders Obtained by Electrochemical Method

2021 ◽  
Vol 316 ◽  
pp. 689-693
Author(s):  
K.D. Naumov ◽  
V.G. Lobanov
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Bulk Density ◽  
Surface Area ◽  
Specific Surface Area ◽  
Current Density ◽  
Zinc Concentration ◽  
Regulatory Change ◽  
Average Particle ◽  
Zinc Powders

The aim of this paper is to establish a regulatory change of zinc powders key physicochemical properties with varying electroextraction conditions. It was studied influence zinc concentration, alkali concentration and current density. Quantitative dependencies of zinc powders particle size and specific surface area from mentioned electroextraction parameters are shown. At increasing of zinc concentration, decreasing of NaOH concentration and decreasing of current density of powders particle size growth, correspondingly specific surface area is declined. It is indicated, that electrolytic zinc powders bulk density varies from 0.61 g/cm3 to 0.75 g/cm3 with a decrease of average particle size from 121 μm to 68 μm. In comparison, spherical powders bulk density used in various industries is currently 2.45-2.6 g/cm3. In all experiments, metal zinc content varied in the range of 91.1-92.5%, the rest - ZnO. To a greater extent, this indicator depends on powder washing quality from alkali and storage conditions.

scholarly journals Synthesis of Spherical Silica by Sol-Gel Method and Its Application as Catalyst Support

2011 ◽  
Vol 10 (2) ◽  
pp. 25
Author(s):  
Anirut Leksomboon ◽  
Bunjerd Jongsomjit
Keyword(s):  
Particle Size ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Weight Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Spherical Silica

In this present study, the spherical silica support was synthesized from tetraethyloxysilane (TEOS), water, sodium hydroxide, ethylene glycol and n-dodecyltrimethyl ammonium bromide (C12TMABr). The particle size was controlled by variation of the ethylene glycol co-solvent weight ratio of a sol-gel method preparation in the range of 0.10 to 0.50. In addition, the particle size apparently increases with high weight ratio of co-solvent, but the particle size distribution was broader. The standard deviation of particle diameter is large when the co-solvent weight ratio is more than 0.35 and less than 0.15. However, the specific surface area was similar for all weight ratios ranging from 1000 to 1300 m2/g. The synthesized silica was spherical and has high specific surface area. The cobalt was impregnated onto the obtained silica to produce the cobalt catalyst used for CO2 hydrogenation.</

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