Electron-optical characterization of nano- and micro-particles in raw and treated waters: an overview

2004 ◽  
Vol 50 (12) ◽  
pp. 1-8 ◽  
Author(s):  
G.G. Leppard ◽  
D. Mavrocordatos ◽  
D. Perret
Keyword(s):  
Natural Waters ◽  
Colloidal Particles ◽  
Size Range ◽  
State Of The Art ◽  
Imaging Techniques ◽  
Nano Particles ◽  
Micro Particles ◽  
Biological Surfaces ◽  
Transmission Electron

State-of-the-art information is presented on the analysis, by transmission electron microscopy (TEM), of aquatic colloidal particles in the size range of 3 to 500 nm least dimension, with a focus on nanoparticles (1-100 nm). Case studies include selections from both natural waters and waters undergoing treatment. The “species” of nano-particles receiving the greatest attention are: humic substances, polysaccharide fibrils, hydrous iron oxides, viruses, clay minerals, refractory cell debris, and heavy metal agglomerates on biological surfaces. Artifacts and how to both detect and minimize them are outlined. Correlative use of TEM with other imaging techniques is emphasized, along with associated spectroscopy. Noted is the potential of computerized image analysis for quantifying colloids on a “per colloid species” basis, using water samples centrifuged onto electron microscope grids.

Coherent electron nanodiffraction from clean silver nano particles in a UHV STEM

1993 ◽  
Vol 51 ◽  
pp. 1058-1059
Author(s):  
J. Liu ◽  
M. Pan ◽  
G. E. Spinnler
Keyword(s):  
Supported Catalysts ◽  
Imaging Techniques ◽  
Nano Particles ◽  
Metal Particles ◽  
Shape Structure ◽  
Dynamical Simulations ◽  
Small Metal Particles ◽  
Extract Information

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.

scholarly journals MICROWAVE ASSISTED SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NICKEL OXIDE NANOPARTICLES

2016 ◽  
Vol 3 (1) ◽  
pp. 12-14
Author(s):  
Kalpanadevi K ◽  
Manimekalai R
Keyword(s):  
Electron Microscope ◽  
Nickel Oxide ◽  
Structural Characterization ◽  
Nano Particles ◽  
Microwave Assisted Synthesis ◽  
Nio Nanoparticles ◽  
Nickel Oxide Nanoparticles ◽  
Transmission Electron ◽  
Good Crystallinity

Nickel oxide (NiO) nano-particles were produced via a simple microwave method from the Ni(OH)2 precursor, which was obtained by slow drop-wise addition of 0.1M sodium hydroxide to 0.1M nickel nitrate. The mixture was vigorously stirred until the pH reached 7.2. The mixture was then irradiated with microwave to deposit Ni(OH)2 at a better precipitation rate. Drying the precipitate at 320°C resulted in formation of NiO nanoparticles. High Resolution Transmission Electron Microscope (HRTEM), Scanning Electron Microscope (SEM) and X-ray diffraction (XRD), employed for the structural characterization of the as-prepared NiO nanoparticles, revealed their good crystallinity and high-purity. Microwave irradiation increased homogeneity and decreased the mean particle size of the produced NiO particles.

PREPARATION, MORPHOLOGY AND MECHANICAL PROPERTIES OF EPOXY NANOCOMPOSITES WITH ALUMINA FILLERS

2010 ◽  
Vol 24 (01n02) ◽  
pp. 136-147 ◽  
Author(s):  
SHEAU HOOI LIM ◽  
KAIYANG ZENG ◽  
CHAOBIN HE
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Thermomechanical Properties ◽  
Nano Particles ◽  
Testing Methods ◽  
Transmission Electron ◽  
Alumina Particles ◽  
Thermomechanical Testing ◽  
Platelet Shape

This paper presents recent studies on the processing and characterization of epoxy-alumina nanocomposites. Nano-sized alumina particles are incorporated into epoxy resin via solvent-assisted method, so that the particles are dispersed homogeneously in the epoxy matrix. The morphologies, mechanical and thermomechanical properties of the resulting nanocomposites are studied using transmission electron microscope (TEM), conventional tensile testing and thermomechanical testing methods. TEM results show that the alumina nano-particles with a higher specific surface area tend to agglomerate. Furthermore platelet shape particles shows a better dispersion homogeneity as well as better improvement in the mechanical properties of the composites compared to the rod shape particles.

Characterization of Nanostructured Nickel Aluminate Formation during Mechano-Chemical Recycling of Spent NiO/Al2O3 Catalyst

2011 ◽  
Vol 364 ◽  
pp. 186-190
Author(s):  
Karim Nazemi Mohammad ◽  
Saeed Sheibani ◽  
Fereshteh Rashchi ◽  
Victor Gonzalez De La Cruz ◽  
Alfonso Caballero Martínez
Keyword(s):  
Electron Microscopy ◽  
Size Range ◽  
Spherical Shape ◽  
Research Use ◽  
Chemical Recycling ◽  
X Ray Diffraction ◽  
Nickel Aluminate ◽  
X Ray ◽  
Transmission Electron

In this research, use of mechanical alloying method, as a new and effective route for the recycling of spent NiO/Al2O3catalyst to nanostructured nickel aluminate spinel was investigated. Samples were characterized using different techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). It was found that the formation of NiAl2O4was started between 15 to 20 hours of milling and completed after 60 hours. The final particles had relatively spherical shape with the size range of 5-50 nm.

scholarly journals Unraveling the complexity of amyloid polymorphism using gold nanoparticles and cryo-EM

2020 ◽  
Vol 117 (12) ◽  
pp. 6866-6874 ◽  
Author(s):  
Urszula Cendrowska ◽  
Paulo Jacob Silva ◽  
Nadine Ait-Bouziad ◽  
Marie Müller ◽  
Zekiye Pelin Guven ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Amyloid Fibrils ◽  
Imaging Techniques ◽  
Postmortem Brain ◽  
Structural Basis ◽  
Transmission Electron

Increasing evidence suggests that amyloid polymorphism gives rise to different strains of amyloids with distinct toxicities and pathology-spreading properties. Validating this hypothesis is challenging due to a lack of tools and methods that allow for the direct characterization of amyloid polymorphism in hydrated and complex biological samples. Here, we report on the development of 11-mercapto-1-undecanesulfonate-coated gold nanoparticles (NPs) that efficiently label the edges of synthetic, recombinant, and native amyloid fibrils derived from different amyloidogenic proteins. We demonstrate that these NPs represent powerful tools for assessing amyloid morphological polymorphism, using cryogenic transmission electron microscopy (cryo-EM). The NPs allowed for the visualization of morphological features that are not directly observed using standard imaging techniques, including transmission electron microscopy with use of the negative stain or cryo-EM imaging. The use of these NPs to label native paired helical filaments (PHFs) from the postmortem brain of a patient with Alzheimer’s disease, as well as amyloid fibrils extracted from the heart tissue of a patient suffering from systemic amyloid light-chain amyloidosis, revealed a high degree of homogeneity across the fibrils derived from human tissue in comparison with fibrils aggregated in vitro. These findings are consistent with, and strongly support, the emerging view that the physiologic milieu is a key determinant of amyloid fibril strains. Together, these advances should not only facilitate the profiling and characterization of amyloids for structural studies by cryo-EM, but also pave the way to elucidate the structural basis of amyloid strains and toxicity, and possibly the correlation between the pathological and clinical heterogeneity of amyloid diseases.

Preparation, Characterization of Co3O4 Nano-Particles and its Catalytic Effect on the Combustion of Fuel Rich Propellants

2012 ◽  
Vol 560-561 ◽  
pp. 284-288 ◽  
Author(s):  
Wei Qiang Pang ◽  
Xiao Bing Shi ◽  
Yang Li
Keyword(s):  
Particle Size ◽  
Catalytic Effect ◽  
Solid Phase ◽  
Particle Size Analysis ◽  
Nano Particles ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Wide Size Distribution

The mono-dispersed Co3O4 nano-particles were prepared by means of solid phase synthetical method. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by laser particle size analysis, x-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The catalytic effects of nano-particles on the combustion of fuel rich propellant were investigated. The results show that the Co3O4 nano-particles prepared are uniform and with relatively wide size distribution curve. The catalytic effect of Co3O4 nano-particles on the fuel rich propellant is stronger than those of micro-sized Co3O4 particles and CuO nano-particles.

Synthesis and Characterization of Nano-Hexaferrites SrFe12O19 by Aqueous Solution Method

2011 ◽  
Vol 306-307 ◽  
pp. 404-409 ◽  
Author(s):  
Jian An Liu ◽  
Mei Mei Zhang ◽  
Yan Fei Zhang ◽  
Shu Jiang Liu
Keyword(s):  
Aqueous Solution ◽  
Magnetic Properties ◽  
Solution Method ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
Nanometer Materials ◽  
Transmission Electron ◽  
Fast Synthesis ◽  
Aqueous Solution Method

Nano-hexaferrite SrFe12O19 has been prepared using the aqueous solution method. The structure and magnetic properties of SrFe12O19 have systematically been investigated by X-ray diffraction (XRD), Thermo gravimetric (TG), Fourier transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM), as well as Vibrating Sample Magnetometer (VSM). The XRD and TEM results showed that the samples are composed of SrFe12O19 nano-particles which are on average 70×50nm in dimensions when treated at 1200°C for 2 hours. The magnetic properties indicated that the saturation magnetization and the intrinsic coercivity were 48 Am2/kg and 506KA/m, respectively. The aqueous solution method is generally applicable to produce the nano-hexaferrite SrFe12O19 and is proved to be a promising method for fast synthesis of nanometer materials using nitrate.

scholarly journals Phytochemical Synthesis and Preliminary Characterization of Silver Nanoparticles Using Hesperidin

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Anish Stephen ◽  
Sankar Seethalakshmi
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Reaction Time ◽  
Silver Nanoparticle ◽  
Size Range ◽  
Transmission Electron ◽  
Vis Spectroscopy

This paper is the first of its kind for development of rapid and ecofriendly method for synthesis of silver nanoparticles from aqueous solution of silver nitrate using the flavonoid “hesperidin” and optimization of the methodology. There is formation of stable spherical silver nanoparticles in the size range of 20–40 nm. Optimization of methodology in terms of concentration of reactants and pH of the reaction mixture reduced the reaction time for silver nanoparticle formation to 2 mins. Silver nanoparticles (AgNPs) were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). UV-vis spectroscopy derived spectrum demonstrated a peak of 430 nm which corresponds to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy revealed spherical shaped silver nanoparticles in the size range of 20–40 nm.

Preparation for Nano-NiO by Electrolysis of Nickel in HOCH2CH2OH Solution

2011 ◽  
Vol 399-401 ◽  
pp. 593-596
Author(s):  
Chuan Gao Zhu ◽  
Feng Wu Wang
Keyword(s):  
High Purity ◽  
Sol Gel ◽  
Nano Particles ◽  
Metal Alkoxide ◽  
Oxide Material ◽  
X Ray Diffraction ◽  
Laser Raman ◽  
Transmission Electron ◽  
Laser Raman Spectra

A method to prepare nickel oxide material which has a high purity and nano-sized particle was developed. nano NiO was synthesized by sol-gel method using nickel alkoxide as precursors. The structural characterization of the obtained materials was performed by thermal analysis TG-DTA, X-ray diffraction (XRD), Laser Raman spectra and Transmission Electron Microscopy (TEM). The characterization results indicated that NiO nano-particles (size 25–35 nm) are obtained by hydrolyzing of metal alkoxide of Ni(OCH2CH2OH)2 and possess high purity.

scholarly journals Characterization of a hybrid polyacrylamide and its flocculation properties in cyanide tailing suspensions

2017 ◽  
Vol 76 (9) ◽  
pp. 2482-2493 ◽  
Author(s):  
Ya Liu ◽  
Cuicui Lv ◽  
Jian Ding ◽  
Peng Qian ◽  
Yang Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Colloidal Particles ◽  
Superior Performance ◽  
Flocculation Mechanism ◽  
Organic Hybrid ◽  
Transmission Electron ◽  
Inverse Microemulsion ◽  
Inverse Microemulsion Polymerization

Abstract An inorganic-organic hybrid flocculant Al(OH)3-polyacrylamide (Al-PAM) with narrow molecular weight distribution was synthesized using inverse microemulsion polymerization. The hybrid polymer Al-PAM was characterized by Infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy, and it was found that it had a ‘star-like’ structure in which Al(OH)3 colloidal particles acted as cores linking PAM chains. The properties of Al-PAM were investigated in flocculating 10 wt% cyanide tailing suspensions. It was found that as the amount of Al-PAMM1 with high molecular weight and aluminum content increased, the initial settling rate of particles accelerated, achieving the maximum 6.6 m/h, 17.3 times the rate of the control without flocculants. The turbidity of the supernatant decreased to 35 ± 2 NTU accordingly, compared to 353 ± 2 NTU of that in the control, which meant that 90.0% of turbidity was removed from the cyanide tailing suspensions. The flocculation mechanism was further explored by floccule size and ζ potential measurements. The superior performance of cationic Al-PAM in flocculating negatively charged particles compared to commercial non-ionic GG indicated that electrostatic repulsion between tailing particles was a crucial factor in deciding the flocculation performance of the polymer. The study demonstrated that both charge neutralization and bridge adsorption were conductive to the particle flocculation.

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