Distribution of carbon black in semicrystalline polypropylene studied by transmission electron microscopy

2002 ◽  
Vol 85 (2) ◽  
pp. 358-365 ◽  
Author(s):  
Jiyun Feng ◽  
Jianxiong Li ◽  
Chi-Ming Chan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Transmission Electron

Three-Dimensional Dispersion of Nano-Fillers in Soft Composite as Revealed by Transmission Electron Microscopy/Electron Tomography (3D-TEM)

2006 ◽  
Vol 514-516 ◽  
pp. 353-358 ◽  
Author(s):  
Shinzo Kohjiya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Natural Rubber ◽  
Structural Information ◽  
Electron Tomography ◽  
Nano Composites ◽  
Nano Structure ◽  
Transmission Electron ◽  
Particulate Silica

. Generally rubber products are a typical soft material, and a composite of a nano-filler (typically, carbon black or particulate silica) and a rubber (natural rubber and various synthetics are used). The properties of these soft nano-composites have been well known to depend on the dispersion of the nano-filler in the rubbery matrix. The most powerful tool for the elucidation of it has been transmission electron microscopy (TEM). The microscopic techniques are based on the projection of 3-dimensional (3D) body on a plane (x, y plane), thus the structural information along the thickness (z axis) direction of the sample is difficult to obtain. This paper describes our recent results on the dispersion of carbon black (CB) and particulate silica in natural rubber (NR) matrix observed by TEM combined with electron tomography (3D-TEM) technique, which enabled us to obtain images of 3D nano-structure of the sample. Thus, 3D images of CB and silica in NR matrix are visualized and analyzed in this communication. These results are precious ones for the design of soft nano-composites, and the technique will become an indispensable one in nanotechnology.

3D Morphological Characterization of Carbon-Black Aggregates Using Transmission Electron Microscopy

1994 ◽  
Vol 67 (2) ◽  
pp. 280-287 ◽  
Author(s):  
Tyler C. Gruber ◽  
T. W. Zerda ◽  
Michel Gerspacher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Three Dimensional ◽  
Reconstruction Algorithm ◽  
Morphological Characterization ◽  
Three Dimensional Modeling ◽  
Transmission Electron ◽  
Best Fitting ◽  
Using Data

Abstract A three-dimensional modeling technique is used to characterize the structure of carbon-black aggregates. The relative positions of individual particles in aggregates are determined using transmission electron microscopy (TEM). Data are acquired from two-dimensional projections taken with the aggregates at two different orientations with respect to the electron beam. Computerized aggregate models are generated using data from TEM projections in our reconstruction algorithm. Inspection of these models shows that their projections very closely replicate the TEM micrographs. Quantitative analysis of the aggregate models reveals that aggregates generally exhibit anisotropy, in the form of a reduction of aggregate breadth, or “flatness,” in one direction. The flat sides tend to align preferentially, along the plane of the TEM sample grid. The dimensions for each aggregate with respect to its best-fitting plane of flatness are determined, and are related through a “flatness index.”

scholarly journals Investigation of Lithiated Carbons by Transmission Electron Microscopy and X-Ray Diffraction Analysis

1998 ◽  
Vol 548 ◽  
Author(s):  
T. D. Tran ◽  
X. Y. Song ◽  
K. Kinoshita
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Lattice Image ◽  
X Ray ◽  
Storage Mechanism ◽  
Transmission Electron ◽  
Diffraction Patterns

ABSTRACTThe microstructures of lithiated synthetic graphite and carbon black were studied by high- resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) analysis. Information about the crystal structure of carbon containing various Li compositions can provide useful insights to our understanding of the Li storage mechanism in carbonaceous materials. Samples with compositions of Li0.93C6or Li0.45C6 were found to contain both stage-one and stage-two compounds. These observations are consistent with XRD data. The changes in sample microstructure as the results of lithiation and exposure to electron irradiation were observed by TEM and recorded over several minutes in the microscope environment. Selected area electron diffraction patterns indicated that the lithiated samples quickly changed composition to LiC 24, which appeared to dominate during the brief analysis period. The layer planes in the lattice image of a disordered carbon black after Li insertion are poorly defined, and changes in the microstructure of these lithiated carbons was not readily apparent. Observations on these lithium intercalation compounds as well as the limitation of the experimental procedure will be presented.

Characterization of Dispersions

1991 ◽  
Vol 64 (3) ◽  
pp. 386-449 ◽  
Author(s):  
W. M. Hess
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Phase Distribution ◽  
Automated Image Analysis ◽  
Carbon Blacks ◽  
Transmission Electron ◽  
Vehicle Systems ◽  
Scanning Electron

Abstract The methods of pigment dispersion analysis have been reviewed in regard to their application to rubber, plastics, and other vehicle systems. The characteristics of dispersions have been divided into three categories: (1) agglomeration (2) microdispersion (networking) and (3) polymer-phase distribution. Stylus roughness measurements on cut surfaces offer the combination of simplicity and speed of operation with high accuracy and precision for measuring pigment agglomeration in elastomer systems of known composition. This method may also be applied to the surface of thin plastic extrudates. However, optical analyses of thin cryosections are preferred for most plastics or unknown rubber compounds containing high loadings of carbon black. X-radiography is generally preferable for the analysis of inorganic agglomeration in most polymeric vehicle systems. The scanning electron microscope is also applicable for this type of analysis and has the added capability of identifying unknown agglomerates by energy dispersive x-ray analysis. Automated image-analysis techniques may also be utilized in conjunction with microscopical methods for quantifying the agglomeration of most types of pigments. For carbon blacks, the most suitable materials for on-line image analyses with transmitted light are plastics, paints, and inks which contain low black loadings. Higher carbon-black loadings in rubber can be analyzed by incident light using metallographic polishing of sulfur-hardened specimens. The microdispersion of carbon blacks at the primary aggregate level can be measured by means of electrical conductivity. This method is not applicable to inorganic pigments, large-particle-size carbon blacks, or blacks at very high or low loadings. Pigment microdispersion in different vehicle systems may also be assessed by means of scanning electron microscopy of thick cross sections (plasma etched to enhance contrast) or by transmission electron microscopy of thin cryosections. The tendency for the finer pigments to form 3-dimensional network structures in elastomers may also be measured as a function of the augmentation of dynamic modulus from high to low strain amplitudes. Pigment phase distribution in elastomer blends may be studied by scanning electron microscopy or transmission electron microscopy of thin cryosections, in conjunction with a staining or etching procedure to produce contrast between the separate polymer components. Selective staining is applicable to blends of polymers which differ significantly in their relative levels of unsaturation (e.g., NR/CIIR). Pyrolytic etching (under vacuum) may be used to produce interzone contrast in blends of polymers which differ significantly in their resistance to thermal degradation (e.g., NR/BR, NR/SBR). Pyrolysis GC may be utilized to determine the amount of carbon black in the separate phases of certain elastomer blends. This method is based on the relative intensity of the primary GC peaks for the individual polymers. The chromatographs are obtained from the bound rubber (carbon-polymer gel) that is developed during the mixing of the compound.

Dynamic Mechanical Thermal Analysis and Transmission Electron Microscopy of Elastomer Blends

1986 ◽  
Vol 59 (4) ◽  
pp. 623-633 ◽  
Author(s):  
K. A. Mazich ◽  
M. A. Samus ◽  
P. C. Killgoar ◽  
H. K. Plummer
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Transmission Electron Microscopy ◽  
Fatigue Life ◽  
Carbon Black ◽  
Two Phase ◽  
Binary Blends ◽  
Dynamic Mechanical ◽  
Transmission Electron ◽  
Cure Temperature

Abstract Dynamic mechanical thermal analysis and transmission electron microscopy have been used to elucidate the structure of binary and ternary blends of NR, BIIR, and IM. Dynamic measurements at 10 Hz were able to resolve loss-tangent peaks into a major peak due to NR and a broad shoulder associated with BIIR and IM. Interpretation of these data in conjunction with electron micrographs indicate that the butyl polymers (BIIR and IM) form a second phase in a matrix of NR for compositions containing at least 67% NR. Dynamic mechanical properties and TEM micrographs of binary blends of NR with BIIR or IM show that the structure of these binary blends differ; IM forms larger, more distinct domains in the NR matrix. This difference in structure may result from the different molecular weights of the butyl polymers and the ability of BIIR to crosslink with NR. TEM micrographs of both binary blends indicate that carbon black is dispersed in the matrix material and is excluded from the isobutylene-rich domains, The two-phase structure of these blends and the partitioning of carbon black between the phases may enhance the fatigue lives of these composites. Cure temperatures in the range from 130°C to 170°C affected the properties and structure of only one blend studied in this work. This blend, an 80:20:20 mixture of NR, BIIR, and IM, respectively, was able to alter its morphology when the cure temperature was elevated. Material cured at 130°C contained domains with a wide variety of shapes and sizes; material cured at 170°C contained uniform, well-defined inclusions. This ternary blend was the only material that also exhibited a higher fatigue life when the cure temperature was raised. Achieving a well-defined dispersion in a two-phase elastomer blend apparently maximizes the fatigue life of the composite material.

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