Scanning Tunneling Microscopy of Carbon Blacks

1993 ◽  
Vol 66 (4) ◽  
pp. 559-566 ◽  
Author(s):  
Seog-Jun Kim ◽  
Darrell H. Reneker
Keyword(s):  
Electron Microscope ◽  
Carbon Black ◽  
Transmission Electron Microscope ◽  
Pyrolytic Graphite ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Carbon Blacks ◽  
Transmission Electron ◽  
Stm Images

Abstract Three kinds of carbon black, HAF (high abrasion furnace, N330), MT (medium thermal, N990), and graphitized MT were observed with the scanning tunneling microscope (STM), the transmission electron microscope (TEM), and the scanning electron microscope (SEM) All the STM images are formed from measurements of the x, t, and z position of points on the surface of the particle. The STM images of carbon blacks were compared to transmission electron microscope (TEM) photographs. Pitted and stepped bumps were observed on the surface of HAF carbon black. The surface of MT carbon black was more rough and disorganized At the atomic scale, ordered structure was found on the surface of HAF carbon-black particles Graphitized MT carbon-black particles were faceted polyhedra. Some facets were smooth while others had multiple terraces. The surface of graphitized MT carbon black was so well ordered that a lattice of carbon atoms similar to HOPG (highly ordered pyrolytic graphite) was observed on the smooth facets.

Filler-Elastomer Interactions. Part XI. Investigation of the Carbon-Black Surface by Scanning Tunneling Microscopy

1994 ◽  
Vol 67 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Meng-Jiao Wang ◽  
Siegfried Wolff ◽  
Burkhard Freund
Keyword(s):  
Carbon Black ◽  
Scanning Tunneling Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Energy Distributions ◽  
Carbon Blacks ◽  
Carbon Black Surface ◽  
Versatile Tool ◽  
Black Surface ◽  
Stm Images

Abstract Scanning tunneling microscopy (STM) has recently been demonstrated to be a powerful and versatile tool to image the microstructure of the surface of carbonaceous materials. In this study, the surfaces of carbon blacks, both graphitized and nongraphitized, were investigated with this technique. The STM images show that the carbon-black surface can be classified into two domains, an organized and an unorganized one. The degree of carbon atom organization varies with the carbon-black grade and increases drastically upon graphitization. The surface energies and energy distributions of graphitized and nongraphitized carbon blacks, measured by inverse gas chromatography, correlate well with their surface microstructure. Mapping of the carbon-black topography showed that although the surface is not smooth, there is no significant porosity either.

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

Images and Applications of Ion Explosion Spike Pits

1990 ◽  
Vol 48 (1) ◽  
pp. 584-585
Author(s):  
P. Fraundorf ◽  
J. Tentschert
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Bulk Material ◽  
Coulomb Repulsion ◽  
The Body ◽  
Atomic Scale ◽  
Early Solar System ◽  
Transmission Electron ◽  
Nuclear Particle ◽  
Particle Tracks

Since the discovery of their etchability in the early 1960‘s, nuclear particle tracks in insulators have had a diverse and exciting history of application to problems ranging from the selective filtration of cancer cells from blood to the detection of 244Pu in the early solar system. Their usefulness stems from the fact that they are comprised of a very thin (e.g. 20-40Å) damage core which etches more rapidly than does the bulk material. In fact, because in many insulators tracks are subject to radiolysis damage (beam annealing) in the transmission electron microscope, the body of knowledge concerning etched tracks far outweighs that associated with latent (unetched) tracks in the transmission electron microscope.With the development of scanned probe microscopies with lateral resolutions on the near atomic scale, a closer look at the structure of unetched nuclear particle tracks, particularly at their point of interface with solid surfaces, is now warranted and we think possible. The ion explosion spike model of track formation, described loosely, suggests that a burst of ionization along the path of a charged particle in an insulator creates an electrostatically unstable array of adjacent ions which eject one another by Coulomb repulsion from substitutional into interstitial sites. Regardless of the mechanism, the ejection process which acts to displace atoms along the track core seems likely to operate at track entry and exit surfaces, with the added feature of mass loss at those surfaces as well. In other words, we predict pits whose size is comparable to the track core width.

Scanning Tunneling Microscopy of Amorphous Carbon Films

1990 ◽  
Vol 48 (1) ◽  
pp. 318-319
Author(s):  
Mircea Fotino ◽  
D.C. Parks
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Amorphous Carbon ◽  
Carbon Films ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Amorphous Carbon Films ◽  
Image Optimization ◽  
Step Procedure ◽  
Stm Images

In the last few years scanning tunneling microscopy (STM) has made it possible and easily accessible to visualize surfaces of conducting specimens at the atomic scale. Such performance allows the detailed characterization of surface morphology in an increasing spectrum of applications in a wide variety of fields. Because the basic imaging process in STM differs fundamentally from its equivalent in other well-established microscopies, good understanding of the imaging mechanism in STM enables one to grasp the correct information content in STM images. It thus appears appropriate to explore by STM the structure of amorphous carbon films because they are used in many applications, in particular in the investigation of delicate biological specimens that may be altered through the preparation procedures.All STM images in the present study were obtained with the commercial instrument Nanoscope II (Digital Instruments, Inc., Santa Barbara, California). Since the importance of the scanning tip for image optimization and artifact reduction cannot be sufficiently emphasized, as stressed by early analyses of STM image formation, great attention has been directed toward adopting the most satisfactory tip geometry. The tips used here consisted either of mechanically sheared Pt/Ir wire (90:10, 0.010" diameter) or of etched W wire (0.030" diameter). The latter were eventually preferred after a two-step procedure for etching in NaOH was found to produce routinely tips with one or more short whiskers that are essentially rigid, uniform and sharp (Fig. 1) . Under these circumstances, atomic-resolution images of cleaved highly-ordered pyro-lytic graphite (HOPG) were reproducibly and readily attained as a standard criterion for easily recognizable and satisfactory performance (Fig. 2).

scholarly journals Mono- and multilayers of molecular spoked carbazole wheels on graphite

2014 ◽  
Vol 10 ◽  
pp. 2783-2788 ◽  
Author(s):  
Stefan-S Jester ◽  
A Vikas Aggarwal ◽  
Daniel Kalle ◽  
Sigurd Höger
Keyword(s):  
Octanoic Acid ◽  
Pyrolytic Graphite ◽  
Self Assembled Monolayers ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Chemical Structures ◽  
Rigid Objects ◽  
Assembled Monolayers ◽  
Stm Images ◽  
Insight Into

Self-assembled monolayers of a molecular spoked wheel (a shape-persistent macrocycle with an intraannular spoke/hub system) and its synthetic precursor are investigated by scanning tunneling microscopy (STM) at the liquid/solid interface of 1-octanoic acid and highly oriented pyrolytic graphite. The submolecularly resolved STM images reveal that the molecules indeed behave as more or less rigid objects of certain sizes and shapes – depending on their chemical structures. In addition, the images provide insight into the multilayer growth of the molecular spoked wheels (MSWs), where the first adlayer acts as a template for the commensurate adsorption of molecules in the second layer.

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