Phase Evolution and Formation Mechanism in Acicular Mullite Prepared from Kaolinite via Wet Chemistry Method

2010 ◽  
Vol 152-153 ◽  
pp. 643-647
Author(s):  
Xiao Chun Dai ◽  
Zhu Fa Zhou ◽  
Shu Mei Wang ◽  
Ran Ran Tian ◽  
Chun Rong Wang ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Formation Mechanism ◽  
Phase Evolution ◽  
Molar Ratio ◽  
Wet Chemistry ◽  
Chemistry Method ◽  
Acicular Mullite

Mullite was synthesized by firing precursors prepared from kaolinite via a wet chemistry method at various temperatures. The acicular mullite grains were formed in samples with addition of AlF3 by this process. The phase evolution and morphology of the fired samples were investigated. For the samples without AlF3, the mullitization began to occur at 1300 and almost completed at 1550 , the grains formed were normal-shaped. For the samples with AlF3, acicular mullite was formed, and mullitization began to occur at 1100 and completed at 1250 . The growth of the acicular mullite was associated with a liquid phase. The formed acicular mullite was alumina-rich and had a composition of about 73.4 wt% Al2O3 and 26.6 wt% SiO2 (Al2O3/SiO2=1.65, molar ratio).

Stress – Strain Analysis on ZnO Nanostructures Synthesized via Wet Chemistry Method

2015 ◽  
Vol 1112 ◽  
pp. 57-61 ◽  
Author(s):  
Amalia Sholehah ◽  
Akhmad Herman Yuwono
Keyword(s):  
Crystallite Size ◽  
Strain Analysis ◽  
Xrd Analysis ◽  
Heating Process ◽  
Zno Nanostructures ◽  
Stress Strain ◽  
Wet Chemistry ◽  
Chemistry Method ◽  
Hall Method ◽  
Scherrer Equation

In the present work, ZnO nanostructures were synthesized via wet chemistry method. The seeding solution was prepared from zinc nitrate tetrahydrate and hexamethylenetetramine. Prior to the heating process, the seeding solution was immersed in cold bath (0°C). XRD analysis had shown sharp peaks in diffractogram, indicating the high crystallinity of ZnO nanostructures. The crystallite size was determined using Scherrer equation and Williamson-Hall method. Other relevant parameters including stress, strain, and energy density were calculated using Williamson-Hall assuming UDM, UDSM, and UDEDM. The results had revealed that crystallite size calculated with Williamson-Hall method is more accurate than Scherrer equation.

Synthesis and Self-Assembly of Ultrathin NixFe1−x(OH)2 Nanodiscs via a Wet-Chemistry Method

2011 ◽  
Vol 11 (12) ◽  
pp. 11028-11031 ◽  
Author(s):  
Dan Zhou ◽  
Markus Boese ◽  
Rongming Wang ◽  
Hongzhou Zhang
Keyword(s):  
Self Assembly ◽  
Wet Chemistry ◽  
Chemistry Method

Oxygen-defective ZnO porous nanosheets modified by carbon dots to improve their visible-light photocatalytic activity and gain mechanistic insight

2020 ◽  
Vol 44 (26) ◽  
pp. 11215-11223 ◽  
Author(s):  
Feng Guo ◽  
Haoran Sun ◽  
Lei Cheng ◽  
Weilong Shi
Keyword(s):  
Photocatalytic Activity ◽  
Liquid Phase ◽  
Visible Light ◽  
Carbon Dots ◽  
Composite Photocatalyst ◽  
Wet Chemistry ◽  
Mechanistic Insight ◽  
Porous Nanosheets ◽  
One Step ◽  
Visible Light Photocatalytic

A carbon dots/oxygen-defective ZnO (COZ) porous nanosheet composite photocatalyst was prepared via a one-step liquid-phase wet chemistry method for the highly efficient visible-light photocatalytic degradation of tetracycline (TC).

scholarly journals Entropy‐Maximized Synthesis of Multimetallic Nanoparticle Catalysts via a Ultrasonication‐Assisted Wet Chemistry Method under Ambient Conditions

2019 ◽  
Vol 6 (7) ◽  
pp. 1900015 ◽  
Author(s):  
Miaomiao Liu ◽  
Zihao Zhang ◽  
Francis Okejiri ◽  
Shize Yang ◽  
Shenghu Zhou ◽  
...  
Keyword(s):  
Ambient Conditions ◽  
Wet Chemistry ◽  
Nanoparticle Catalysts ◽  
Chemistry Method

scholarly journals Synthesis and structural characterization of Ca12Ga14O33

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sabrina E. A. McCoy ◽  
John R. Salasin ◽  
S. Michelle Everett ◽  
Claudia J. Rawn
Keyword(s):  
Powder Diffraction ◽  
Structural Model ◽  
Electronic Band Structure ◽  
Rietveld Method ◽  
Experimental Studies ◽  
Phase Evolution ◽  
Neutron Powder Diffraction ◽  
Electronic Band ◽  
Wet Chemistry ◽  
X Ray

Abstract Ca12Ga14O33 was successfully synthesized using a wet chemistry technique to promote the homogenous mixing of the Ca and Ga cations. Rietveld refinements on X-ray and neutron powder diffraction data confirm that the compound is isostructural to Ca12Al14O33, however, with a significantly larger lattice parameter allowing for the cages that result from the framework arrangement to expand. In naturally occurring Ca12Al14O33, the mineral mayenite, these cages are occupied by O2− anions, however, experimental studies exchanging the O2− anions with other anions has led to a host of applications, depending on the caged anion. The functional nature of the structure, where framework distortions coupled with cage occupants, are correlated to electronic band structure and modifications to the framework could lead to interesting physical properties. The phase evolution was tracked using thermogravimetric analysis and high temperature X-ray diffraction and showed a lower formation temperature for the Ca12Ga14O33 analogue compared to Ca12Al14O33 synthesized using the same wet chemistry technique. Analyzing both X-ray and neutron powder diffraction using the Rietveld method with two different starting models results in one structural model, with one Ca position and the caged O on a 24d special position, being preferred.

scholarly journals Synthesis and Characterization of Zirconium Nitride Nanopowders by Internal Gelation and Carbothermic Nitridation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shijiao Zhao ◽  
Jingtao Ma ◽  
Rui Xu ◽  
Xuping Lin ◽  
Xing Cheng ◽  
...  
Keyword(s):  
Carbon Black ◽  
Chemical Properties ◽  
Phase Evolution ◽  
Zirconium Nitride ◽  
Molar Ratio ◽  
Nitridation Process ◽  
Zirconium Compounds ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractZirconium compounds has been widely attention over the last decades due to its excellent physical and chemical properties. Zirconium nitride nanopowders were synthesized via a simple direct carbothermic nitridation process of internal gel derived zirconia in the presence of nano-sized carbon black. The effects of reaction temperature, dwell time and molar ratio of carbon black to Zr (C/Zr) on the phase composition, grain size and crystal parameters of products were studied. Based upon the analysis of crystallite phase evolution and microstructure characterization, it was found that zirconium oxynitride is intermediate product and then O atoms in oxynitride were extracted by oxygen getter, carbon black. Anion sites were directly replaced by N atoms to form rock-salt type nitride in carbothermic nitridation process.

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