Preparation of Platinum Nanoparticles in Heterogeneous Solid-Liquid System by Ultrasound and Microwave Irradiation

2008 ◽  
Vol 8 (9) ◽  
pp. 4482-4487 ◽  
Author(s):  
Dai Ishikawa ◽  
Yamato Hayashi ◽  
Hirotsugu Takizawa
Keyword(s):  
Microwave Irradiation ◽  
Platinum Nanoparticles ◽  
Liquid System ◽  
Solid Liquid ◽  
Heterogeneous Solid

Preparation of Platinum Nanoparticles in Heterogeneous Solid-Liquid System by Ultrasound and Microwave Irradiation

2008 ◽  
Vol 8 (9) ◽  
pp. 4482-4487 ◽  
Author(s):  
Dai Ishikawa ◽  
Yamato Hayashi ◽  
Hirotsugu Takizawa
Keyword(s):  
Microwave Irradiation ◽  
Fine Particles ◽  
Pt Nanoparticles ◽  
Ultrasound Irradiation ◽  
Liquid System ◽  
Homogeneous Distribution ◽  
Scattering Method ◽  
X Ray ◽  
Dynamic Light Scattering Method ◽  
Solid Liquid

Pt nanoparticles and Pt/spherical carbon (SC) were prepared in a heterogeneous (PtO2/SC, water/ethanol) solid-liquid system without dispersant using ultrasound and microwave irradiation. The Pt nanoparticles and Pt/SC were characterized using X-ray diffraction (XRD), transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDX), and dynamic light scattering method for particle size determination. The average size of the Pt nanoparticles prepared by only ultrasound irradiation was smaller than that prepared by microwave irradiation. Pt nanoparticles were successfully prepared by microwave irradiation with a reaction time of several minutes at a specific concentration of diluted ethanol. Pt/SC prepared by combined ultrasound and microwave irradiation resulted in fine particles with good homogeneous distribution.

Comparison of betaine and l-stachydrine as phase-transfer catalysts in Michael addition and Darzens reaction

2006 ◽  
Vol 60 (5) ◽  
Author(s):  
E. Veverková ◽  
R. Droppová ◽  
Š. Toma
Keyword(s):  
Microwave Irradiation ◽  
Michael Addition ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Phase Transfer ◽  
Liquid System ◽  
Darzens Reaction ◽  
Phase Transfer Catalysts ◽  
Solid Liquid

AbstractBetaine and l-stachydrine have been tested as phase-transfer catalysts in Michael and Darzens reactions. The catalytic effect of l-stachydrine was found comparable to that of betaine in Michael addition and even higher when considering Darzens reaction. The desired products have been obtained in higher yields in solid-liquid system than under liquid-liquid bi-phase conditions. The influence of microwave irradiation and ultrasound on the reaction rate has been studied.

The Use of High Energies Radiations to Characterise Solid-Liquid Systems

2005 ◽  
Vol 498-499 ◽  
pp. 49-54 ◽  
Author(s):  
Fábio de Oliveira Arouca ◽  
João Jorge Ribeiro Damasceno
Keyword(s):  
Gamma Rays ◽  
Constitutive Equations ◽  
Liquid System ◽  
Local Concentration ◽  
High Energies ◽  
Transient Regimes ◽  
Medium Permeability ◽  
Liquid Systems ◽  
And Performance ◽  
Solid Liquid

The behavior of an isothermal and non-reaction solid-liquid system can be model using a mathematical model based on the Mixtures’ Theory of Continuum Mechanics. The knowledge of the constitutive equations of this phenomenon, as pressure on the solids and medium permeability, is very important in the design and performance evaluation of the continuous thickeners or filters. In this work the batch sedimentation phenomena of a kaolin aqueous suspensions was investigated. The technique consists on measuring of the gamma rays attenuation when they cross the physical media as a function of the local concentration at several vertical positions in a reservoir. Using the experimental data and local concentration as a function of the attenuation curve, it is possible to determine the constitutive equations. The results were satisfactory, allowing simulations of this phenomenon for steady and transient regimes in future papers.

Mechanistic modelling of kinetics and mass transfer for a solid–liquid system: Leaching of zinc with ferric iron

2010 ◽  
Vol 65 (15) ◽  
pp. 4460-4471 ◽  
Author(s):  
Tapio Salmi ◽  
Henrik Grénman ◽  
Heidi Bernas ◽  
Johan Wärnå ◽  
Dmitry Yu. Murzin
Keyword(s):  
Mass Transfer ◽  
Ferric Iron ◽  
Liquid System ◽  
Mechanistic Modelling ◽  
Solid Liquid

Facile Synthesis of Polysubstituted Cyclopropanes in a Two-Phase Solid-Liquid System

1992 ◽  
Vol 22 (12) ◽  
pp. 1651-1653 ◽  
Author(s):  
Yan Chaoguo ◽  
Kong Qiangzhi ◽  
Lu Wenxing ◽  
Wu Jitao
Keyword(s):  
Liquid System ◽  
Facile Synthesis ◽  
Two Phase ◽  
Solid Liquid

scholarly journals Improved Understanding of the Sulfidization Mechanism in Amine Flotation of Smithsonite: An XPS, AFM and UV–Vis DRS Study

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 370 ◽  
Author(s):  
Ruizeng Liu ◽  
Bin Pei ◽  
Zhicheng Liu ◽  
Yunwei Wang ◽  
Jialei Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
High Reactivity ◽  
Phase Imaging ◽  
Solid Product ◽  
Force Microscopy ◽  
Atomic Force ◽  
Liquid Reaction ◽  
Solid Liquid ◽  
Heterogeneous Solid

Sulfidization is required in the amine flotation of smithsonite; however, the sulfidization mechanism of smithsonite is still not fully understood. In this work, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and UV–vis diffuse reflectance spectroscopy (UV–vis DRS) were used to characterize sulfidized and unsulfidized smithsonite. The XPS and UV–vis DRS analyses showed that smithsonite sulfidization is a transformation of ZnCO3 to ZnS on the smithsonite surfaces. However, this transformation is localized, resulting in the coexistence of ZnCO3 and ZnS or in the formation of ZnS island structures on the sulfidized smithsonite surfaces. AFM height imaging showed that sulfidization can substantially change the surface morphology of smithsonite; in addition, AFM phase imaging demonstrated that sulfidization occurs locally on the smithsonite surfaces. Based on our findings, it can be concluded that smithsonite sulfidization is clearly a heterogeneous solid–liquid reaction in which the solid product attaches at the surfaces of unreacted smithsonite. Smithsonite sulfidization involves heterogeneous nucleation and growth of ZnS nuclei. Moreover, the ZnS might nucleate and grow preferentially in the regions with high reactivity, which might account for the formation of ZnS island structures. In addition, sphalerite-structured ZnS is more likely to be the sulfidization product of smithsonite under flotation-relevantconditions, as also demonstrated by the results of our UV–vis DRS analyses. The results of this study can provide deeper insights into the sulfidization mechanism of smithsonite.

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