Particle size distribution and morphological changes in activated carbon-metal oxide hybrid catalysts prepared under different heating conditions

2015 ◽  
Vol 261 (3) ◽  
pp. 227-242 ◽  
Author(s):  
A. BARROSO-BOGEAT ◽  
M. ALEXANDRE-FRANCO ◽  
C. FERNÁNDEZ-GONZÁLEZ ◽  
V. GÓMEZ-SERRANO
2019 ◽  
Vol 7 (23) ◽  
pp. 6932-6940 ◽  
Author(s):  
Xing Feng ◽  
Jun Zhang ◽  
Zhen Hu ◽  
Qingsong Wang ◽  
Md. Monarul Islam ◽  
...  

The morphology of pyrene-based AIEgens changes depending on the water fraction. The different size distribution and morphological changes of nano-particle species play a significant role in enhancing the emission intensity in the aggregated state.


2004 ◽  
Vol 449-452 ◽  
pp. 1237-1240 ◽  
Author(s):  
Hwan Pil Park ◽  
Yoon Chung ◽  
Chong Seung Yoon ◽  
Sung Su Jo ◽  
Young Ho Kim

We developed a simple method of producing metal oxide nanoparticles by reacting a polyamic acid (PAA) with Cu or Sn metal films. Respective particle size, distribution, and morphology were characterized by transmission electron microscopy (TEM). The morphology of metal oxides dispersed in the polyimide is different in Cu and Sn metal films. The Cu2O particles were formed by the dissolution reaction between the polyamic acid and the Cu films. During curing, PAA dehydrates and converts to polyimide, accompanied by precipitation of Cu2O particles. The synthesized Cu2O particles were randomly dispersed within the polyimide. And their particle size was relatively uniform, having a narrow distribution. Mostly nanosize Cu2O particles were formed in the specimen made from 10 nm thick Cu film and the mixture of nanosize particles and Cu layers were observed in the 30 nm thick Cu film. On the other hands, the Sn film undergoes surface reaction with the polyamic acid. Therefore, the synthesized SnO2 particles existed only at the surface of the substrate. SnO2 particle size distribution was not uniform in the polyimide. Although particles were not distributed uniformly in the polyimide, they were confined in a monolayer. The different particle distributions were attributed to the reactivity difference of PAA with Cu and Sn films.


2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Eddy Heraldy ◽  
Khoirina Dwi Nugrahaningtyas ◽  
Heriyanto Heriyanto

<p>The study of calcination treatment at 450°C on Ca-Mg-Al-hydrotalcite from brine water has been investigated. Characterization by XRD shows that Ca-Mg-Al hydrotalcite compound has found hydrotalcite phase and another phase such as Mg(OH)<sub>2</sub>, Al(OH)<sub>3</sub> and CaCO<sub>3</sub>. These results are confirmed by the presence of hydroxyl groups, M-O and M-OH groups (M is Mg, Ca and Al) at wavenumber region around 3464.35 cm<sup>-1</sup>, 447.50 cm<sup>-1</sup> and 531.41 cm<sup>-1</sup>. The calcination effect on Ca-Mg-Al hydrotalcite compounds at 450ºC being led to changes in structure become an metal oxide such as MgO, CaO, Al<sub>2</sub>O<sub>3</sub>, MgAl<sub>2</sub>O<sub>4</sub> and CaCO<sub>3</sub>. These results are confirmed from decreasing on the absorption peak of M-OH group at wavenumbers region around 531.41 cm<sup>-1</sup> and 786.99 cm<sup>-1</sup> and widening of the absorption region at 500-900 cm<sup>-1</sup>. Consequently, the calcination treatment successfully increased the surface area of Ca-Mg-Al hydrotalcite compounds from 97.4 m<sup>2</sup>/g to 156.826 m<sup>2</sup>/g. Morphology of Ca-Mg-Al hydrotalcite changes the shape from a big to be small shape and the particle size distribution of 0-0.25 μm into 0-1 μm. Thermal analysis showed changes in the structure of hydrotalcite into oxide begins at a temperature of 265°C and started to become oxide completely after the temperature reaches 428°C.</p>


1983 ◽  
Vol 28 ◽  
Author(s):  
R.D. Kissinger ◽  
S.V. Nair ◽  
J.K. Tien

ABSTRACTThe kinetics of powder consolidation, or densification, and the powder morphological changes ocurring during hot isostatic pressing (HIP) are studied as a function of particle size distribution and hold time at HIP temperature for the nickel base superalloy RENE-95. In order to understand the extent of individual powder particle deformation during consolidation and its effect on subsequent prior particle boundaries (PPB), particle size distribution was studied as a variable. Particle size distributions studied include monosized (75–90 um), bimodal ( 75–90 um and 33–35 um) and commercial (<104 um) size distributions. The experimental results of HIP densification kinetics are compared with a newly developed analytical deformation mechanism model for HIP consolidaiton which takes into account the effect of a distribution of particle sizes on the kinetics of densification.


2020 ◽  
Vol 169 ◽  
pp. 01025
Author(s):  
Inna Zamulina ◽  
Marina Burachevskaya ◽  
Saglara Mandzhieva ◽  
Tatiana Bauer ◽  
Anatolii Barakhov ◽  
...  

In this study, a model experiment was performed under artificial copper contamination of Haplic Chernozem soil. Following the introduction of granular activated carbon (GAC) and biocharin contaminated soil, data on the particle size distribution were obtained. The particle size distribution of Haplic Chernozem was determined by two different methods namely pipette method (PM) and laser diffraction method (LDM). For the LDM, changes in the composition of fractions of more than 0.01 mm were more obvious, while for PM, the main differences were of characteristic for the content of fine fractions less than 0.01 mm.


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