Electron Microscopy Studies of Polymer Blends

1980 ◽  
Vol 38 ◽  
pp. 248-249
Author(s):  
S.Y. Hobbs ◽  
V.H. Watkins ◽  
R.P. Kambour ◽  
R.C. Bopp
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Separation ◽  
Phase System ◽  
Segregation Behavior ◽  
Phenylene Oxide ◽  
Transmission Electron ◽  
Microscopic Studies ◽  
Phase Separation Behavior ◽  
Separation Behavior

Scanning and transmission electron microscopy have been used to investigate the phase separation behavior of blends of brominated poly (2,6-dimethy1 -1 ,4-phenylene oxide) known trivially as poly (xylenyl ether) (PXE) and polystyrene. DSC scans show that when more than 85% of the PXE rings are brominated, the blends exhibit two glass temperatures centered at 100°C and 290°C and the polymers are immiscible.1 At lower bromine concentrations, a single composition dependent Tg characteristic of a one phase system is observed. Microscopic studies, however, indicate that separate phases which can not be detected ca1orimetrica11y may persist to considerably lower levels of bromination and may thus provide a more sensitive measure of segregation behavior.

scholarly journals Alloy Design, Thermodynamics, and Electron Microscopy of Ternary Ti-Ag-Nb Alloy with Liquid Phase Separation

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5268
Author(s):  
Takeshi Nagase
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Separation ◽  
Liquid Phase ◽  
Alloy System ◽  
Liquid Phase Separation ◽  
Mixing Enthalpy ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons

The Ti–Ag alloy system is an important constituent of dental casting materials and metallic biomaterials with antibacterial functions. The binary Ti–Ag alloy system is characterized by flat liquidus lines with metastable liquid miscibility gaps in the phase diagram. The ternary Ti–Ag-based alloys with liquid phase separation (LPS) were designed based on the mixing enthalpy parameters, thermodynamic calculations using FactSage and Scientific Group Thermodata Europe (SGTE) database, and the predicted ground state diagrams constructed by the Materials Project. The LPS behavior in the ternary Ti–Ag–Nb alloy was investigated using the solidification microstructure analysis in arc-melted ingots and rapidly solidified melt-spun ribbons via trans-scale observations, combined with optical microscopy (OM), scanning electron microscopy (SEM) including electron probe micro analysis (EPMA), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). The solidification microstructures depended on the solidification processing in ternary Ti–Ag–Nb alloys; macroscopic phase-separated structures were observed in the arc-melted ingots, whereas fine Ag globules embedded in the Ti-based matrix were observed in the melt-spun ribbons.

Cross-Sectional TEM Study Of Phase Separation In Reaction Of Ni-Ta Films With GaAs

1985 ◽  
Vol 54 ◽  
Author(s):  
A. Lahav ◽  
M. Eizenberg ◽  
Y. Komem
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Transmission Electron Microscopy ◽  
Phase Separation ◽  
Gaas Substrate ◽  
Auger Spectroscopy ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

ABSTRACTThe reaction between Ni60Ta40 amorphous alloy and (001) GaAs was studied by cross-sectional transmission electron microscopy, Auger spectroscopy, and x-ray diffraction. At 400°C formation of Ni GaAs at the interface with GaAs was observed. After heat treatment at 600°C in vacuum a layered structure of TaAs/NiGa/GaAs has been formed. The NiGa layer has epitaxial relations to the GaAs substrate. The vertical phase separation can be explained by opposite diffusion directions of nickel and arsenic atoms.

Phase separation in SiO2–TiO2 gel and glassy films studied by atomic force microscopy and transmission electron microscopy

2001 ◽  
Vol 16 (6) ◽  
pp. 1626-1631 ◽  
Author(s):  
A. Karthikeyan ◽  
Rui M. Almeida
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Phase Separation ◽  
Sol Gel ◽  
Force Microscopy ◽  
Pure Silica ◽  
Atomic Force ◽  
Transmission Electron

An investigation of phase separation phenomena in gel and glassy thin films of silica–titania, with TiO2 contents of 20 and 40 mol%, has been carried out by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The thin films were prepared by spin coating of a precursor sol on silicon wafers. Both the TEM measurements (carried out on scrapped thin film flakes) and the AFM measurements (carried out on films coated on the silicon substrates) for samples with different heat treatments suggest that spinodal-like structural inhomogeneities occur in these samples, unlike the corresponding observations in pure silica films, which are known to be homogeneous. Changes in the microstructure of the films have been noticed with the thermal treatment, in agreement with earlier x-ray photoemission studies. The finer characteristic dimensions of the phase separated regions reveal that silica–titania samples prepared by sol-gel processing exhibit a more intimate mixing of the phases.

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