Amphiphilic architectures based on fullerene and calixarene platforms: From buckysomes to shape-persistent micelles

2008 ◽  
Vol 80 (3) ◽  
pp. 571-587 ◽  
Author(s):  
Andreas Hirsch
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Transfer ◽  
Size Distribution ◽  
Photoinduced Electron Transfer ◽  
Building Blocks ◽  
Water Soluble ◽  
Narrow Size Distribution ◽  
Transmission Electron ◽  
Supramolecular Aggregation

The supramolecular aggregation properties of new prototypes of artificial amphiphiles consisting of fullerene or calixarene building blocks serving as platforms for the connection of hydrophobic and dendritic hydrophilic groups are reported. Very water-soluble monoadducts of C60 carrying a defined number of negative charges at a given pH were hybridized with cationic porphyrins including cyctochrome C and investigated with respect to photoinduced electron transfer. Fullerene adducts with dendritic deprotected sugar addends self-assemble to supramolecular sugar balls in water with a narrow size distribution of the micelles of around 4 nm. Various examples of cone- or T-shaped amphiphiles involving calixarene and fullerene cores self-organize to the first examples of shape-persistent micelles whose supramolecular arrangement in water has been determined with unprecedented precision based on the analysis of cryo-transmission electron microscopy (TEM) investigations.

Preparation and Characterization of Electrosprayed Nanoparticles containing Ethyl Maltol Flavor

2021 ◽  
Vol 1042 ◽  
pp. 131-136
Author(s):  
Megdi Eltayeb
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Stearic Acid ◽  
Size Distribution ◽  
Entrapment Efficiency ◽  
Narrow Size Distribution ◽  
Transmission Electron

In this study, electrospraying is used to prepare electrosprayed multicomponent nanoparticles of ethylcellulose and stearic acid entrapping ethyl maltol. Electrospraying nanoparticles produced were ≤100 nm diameter and narrow size distribution (polydispersity index 0.26) is achieved. The ethyl maltol entrapment efficiency and yield were approximately 88% and 76%, respectively. The presence of ethyl maltol flavor within the polymeric electrosprayed nanoparticles was shown by Fourier transform infrared spectroscopy. The morphology of the electrosprayed multicomponent nanoparticles generated was studied by transmission electron microscopy.

scholarly journals The Domain and Microstructure of Resin-Bonded Magnets

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2849
Author(s):  
Marcin Jan Dośpiał
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Size Distribution ◽  
Domain Structure ◽  
Grain Size Distribution ◽  
Exchange Interactions ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Scanning Electron

This paper presents domain and structure studies of bonded magnets made from nanocrystalline Nd-(Fe, Co)-B powder. The structure studies were investigated using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Mössbauer spectroscopy and X-ray diffractometry. On the basis of performed qualitative and quantitative phase composition studies, it was found that investigated alloy was mainly composed of Nd2(Fe-Co)14B hard magnetic phase (98 vol%) and a small amount of Nd1.1Fe4B4 paramagnetic phase (2 vol%). The best fit of grain size distribution was achieved for the lognormal function. The mean grain size determined from transmission electron microscopy (TEM) images on the basis of grain size distribution and diffraction pattern using the Bragg equation was about ≈130 nm. HRTEM images showed that over-stoichiometric Nd was mainly distributed on the grain boundaries as a thin amorphous border of 2 nm in width. The domain structure was investigated using a scanning electron microscope and metallographic light microscope, respectively, by Bitter and Kerr methods, and by magnetic force microscopy. Domain structure studies revealed that the observed domain structure had a labyrinth shape, which is typically observed in magnets, where strong exchange interactions between grains are present. The analysis of the domain structure in different states of magnetization revealed the dynamics of the reversal magnetization process.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

Synthesis Route towards Fine and Monodisperse Ni Nanoparticles via Hot-Injection Approach

2013 ◽  
Vol 393 ◽  
pp. 146-151 ◽  
Author(s):  
N.R. Nik Roselina ◽  
Aziz Azizan ◽  
Koay Mei Hyie ◽  
C.M. Mardziah ◽  
Salmiah Kasolang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Size Distribution ◽  
Reaction Rate ◽  
Fine Particles ◽  
Synthesis Temperature ◽  
Ni Nanoparticles ◽  
One Pot ◽  
Transmission Electron ◽  
Hot Injection

Manipulation of adding sequences have been found to influence the reaction rate, thus made it easier to produced controllable Ni nanoparticles. Hot-injection approach shown capability to significantly reduce the production time of Ni nanoparticles compared to the conventional one-pot synthesis. With minor modification on conventional polyol method, narrow, monodispersed and highly yield spherical nickel (Ni) nanoparticles were successfully produced at synthesis temperature of 60°C. Three mixing methods were investigated to study its efficiency towards producing rapid and narrower size distribution of Ni nanoparticles. Reduction processes were proposed each of the method. As-synthesized Ni nanoparticles were characterized with Transmission Electron Microscopy (TEM), Scanning Transmission Electron Microscopy (STEM) and Fourier transform infrared spectroscopy (FTIR) to analyze the size, morphology and interaction of reactants. Fine particles size distribution revealed that when hydrazine was first heated, reaction rate improved tremendously.

An Experimental Study on Synthesis and Characterization of Silica Nanoparticles Prepared by Sol-Gel Method

2007 ◽  
Vol 553 ◽  
pp. 245-251
Author(s):  
Ali Shokuhfar ◽  
Tolou Shokuhfar ◽  
M. Ghazinejad ◽  
R. Babazade ◽  
S. Tabatabae
Keyword(s):  
Electron Microscopy ◽  
Silica Nanoparticles ◽  
Size Distribution ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Industrial Applications ◽  
Silica Particles ◽  
Narrow Size Distribution ◽  
Molar Ratios ◽  
Transmission Electron

Monodispersed nanometer-sized particles proved to be very important and advantageous in many industrial applications. One of the notable groups of these particles is silica (SiO2) nanoparticles which are widely utilized in developing numerous products such as electrical and thermal insulators, humidity sensors, varnish, etc. Since the quality of some of these products depends highly on the purity and size distribution of the silica particles, it is necessary to produce silica nanoparticles of narrow size distribution and very high purity. In this research silica nanoparticles, with a relatively narrow size distribution, have been synthesized via the hydrolysis reaction of tetraethoxisilane (TEOS) in the solution of deionized water and ethanol (C2H5OH), and in the presence of ammonia (NH3) as a catalyst. The nature, morphology and the size of the silica particles has been studied using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and X-ray diffraction. Results indicate that the morphology, structure and the diameter of silica particles depend strongly on the molar ratios of the reactants.

Transmission electron microscopy of intracellular particles of polyethylene from joint replacement prostheses: size distribution and cellular response

Biomaterials ◽  
2001 ◽  
Vol 22 (21) ◽  
pp. 2835-2842 ◽  
Author(s):  
Eric B Benz ◽  
Micheline Federman ◽  
John J Godleski ◽  
Benjamin E Bierbaum ◽  
Thomas S Thornhill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Size Distribution ◽  
Joint Replacement ◽  
Cellular Response ◽  
Transmission Electron

Transmission electron microscopy on metal–organic frameworks – a review

2017 ◽  
Vol 5 (29) ◽  
pp. 14969-14989 ◽  
Author(s):  
Christian Wiktor ◽  
Maria Meledina ◽  
Stuart Turner ◽  
Oleg I. Lebedev ◽  
Roland A. Fischer
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Spatial Distribution ◽  
Chemical Reactions ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Transmission Electron ◽  
Metal Organic ◽  
Surface Facets

Versatile materials like MOFs require careful characterization. TEM can be used to determine and identify the crystal structure and surface facets of MOFs, the spatial distribution of guests or building blocks in them and how they are changed in chemical reactions.

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