Size-Based Speciation of Natural Colloidal Particles by Flow Field Flow Fractionation, Inductively Coupled Plasma-Mass Spectroscopy, and Transmission Electron Microscopy/X-ray Energy Dispersive Spectroscopy:  Colloids−Trace Element Interaction

2006 ◽  
Vol 40 (7) ◽  
pp. 2156-2162 ◽  
Author(s):  
M. Baalousha ◽  
F. V. D. Kammer ◽  
M. Motelica-Heino ◽  
M. Baborowski ◽  
C. Hofmeister ◽  
...  
2000 ◽  
Vol 638 ◽  
Author(s):  
Jordi Arbiol ◽  
Ana Ruiz ◽  
Albert Cirera ◽  
Francisca Peiró ◽  
Albert Cornet ◽  
...  

AbstractIn this work, we studied the Pt particles embedded on crystalline TiO2 nanopowders. As it is well known, metal nanoparticles distributed on TiO2 surface can improve dramatically the reaction rate and selectivity of reaction in gas sensing. We prepared a wide set of TiO2 samples with different nominal Pt concentration. The aim of this study was to analyse the Pt distribution on TiO2 surface (density of Pt, particle size distribution, etc.), as well as the Pt phases existing in our samples. We used High Resolution Transmission Electron Microscopy (HRTEM) as a powerful tool to study Pt particles morphology. The HRTEM images were compared with computer simulations to confirm the results obtained. The chemical composition of the material has been also investigated by Inductively Coupled Plasma (ICP).


Clay Minerals ◽  
2001 ◽  
Vol 36 (3) ◽  
pp. 447-464 ◽  
Author(s):  
J. M. Huggett ◽  
A. S. Gale ◽  
N. Clauer

AbstractVariegated palaeosols, which formed from weathering of clays, silts and brackish to freshwater limestones, are present in the Late Eocene–Early Oligocene Solent Group of the Hampshire Basin, southern UK. The composition and origin of the clay in three segments of the lower part of the Solent Group have been investigated by X-ray diffraction, microprobe analysis, inductively coupled plasma-mas spectrometry, K/Ar dating, high resolution scanning electron microscopy, analytical transmission electron microscopy and wet chemistry. The detrital clay mineral suite is dominated by illite and smectite with minor kaolinite and chlorite. Seasonal wetting and drying in gley soils has resulted in replacement of smectite by Fe-rich, or illite-rich illitesmectite. Illite has also formed with gypsum and calcite in ephemeral hypersaline alkaline lakes that periodically dried out. This illite may have precipitated directly from solution. X-ray diffraction data and probe analyses indicate that the neoformed illite is Fe-rich. The K and Fe for the illitization are thought to be derived from weathered glauconite reworked from the underlying Bracklesham Group and Barton Beds.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1340
Author(s):  
Davide Motta ◽  
Ilaria Barlocco ◽  
Silvio Bellomi ◽  
Alberto Villa ◽  
Nikolaos Dimitratos

In the present work, an Ir/CeO2 catalyst was prepared by the deposition–precipitation method and tested in the decomposition of hydrazine hydrate to hydrogen, which is very important in the development of hydrogen storage materials for fuel cells. The catalyst was characterised using different techniques, i.e., X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with X-ray detector (EDX) and inductively coupled plasma—mass spectroscopy (ICP-MS). The effect of reaction conditions on the activity and selectivity of the material was evaluated in this study, modifying parameters such as temperature, the mass of the catalyst, stirring speed and concentration of base in order to find the optimal conditions of reaction, which allow performing the test in a kinetically limited regime.


2013 ◽  
Vol 716 ◽  
pp. 360-363
Author(s):  
Peng Quan Yao ◽  
Lin Hua Zhu ◽  
Tian Si ◽  
Jin Yang

Several type of gold precursors including pre-synthesized Au (en)2Cl3and gold colloid were tried to intercalate into the layer space of Na-Montmorillonite (Na-MMT). In the preparation, DDA and PAA were employed to cap the pre-synthesized gold colloidal particles and then intercalated into Na-MMT, and the Au (en)2Cl3was directly intercalated to Na-MMT through cation exchange. X-ray diffraction (XRD), fluorescence analysis (XRF) and transmission electron microscopy (TEM) were used to characterize the prepared samples. The results showed that the gold colloid modified by dodecylamine (DDA) and polyallylamine hydrochloride (PAA) respectively were successfully intercalated into the layer gallery of Na-MMT based on the mechanism of covalent capture. However, thermal treatment at 773K for 2h resulted in migration of gold nanoparticles from layer space to the out surface of the Na-MMT.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Narges Vahedi-Notash ◽  
Majid M. Heravi ◽  
Ali Alhampour ◽  
Pourya Mohammadi

Abstract In this research, we reported an effective method for the synthesis of a new mesoporous triazine-based carbon (MTC) substrate and its application as the green and recoverable catalyst in the synthesis of organic compounds. The porous carbon acted as a substrate for silver active species after its surface modification by chloroacetonitrile (Ag@MTC). The Ag@MTC nanocatalyst was characterized by several techniques namely, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller surface area analysis, and inductively coupled plasma. The Ag@MTC catalyst was applied for the reduction of nitroaromatic compounds in aqueous media by using NaBH4 (reducing agent) at room temperature. This nanocatalyst can be readily recovered and recycled for at least nine runs without a notable decrease in its efficiency. Catalytic efficiency studies exhibited that Ag@MTC nanocatalyst had good activity towards reduction reactions.


2013 ◽  
Vol 680 ◽  
pp. 49-53
Author(s):  
Chang Yu ◽  
Xu Zhang ◽  
Kan He ◽  
Yue Liu ◽  
Jie Shan Qiu

A novel biocompatible Fe2+-chitosan (CTS)/citric acid modified carbon nanotube (CA-CNTs) composite (Fe2+-CTS/CA-CNTs) has been successfully synthesized by covalent bonding and crosslinking chemistry, followed by the reduction. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis spectrum, X-ray diffraction (XRD), inductively coupled plasma (ICP), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) techniques. The results show that the CTS has been successfully grafted to the CA-CNTs carrier and Fe2+ ions are absorbed on the CTS by coordination bond mode. It was found that the Fe2+-CTS/CA-CNTs composite shows good magnetic properties with a low ratio of remanence to saturation magnetization and is in a superparamagnetic state at room temperature. It is believed that the Fe2+-CTS/CA-CNTs composite will be potential for application in MRI.


Sign in / Sign up

Export Citation Format

Share Document