Studies by scanning electron microscopy

Nakajima compared the results obtained by SEM and by rheology. With more compatible plasticizers the structure of the PVC particles disappears at lower temperatures than in the case of less compatible plastidzeis. There are some good solvents at lower temperatures that become bad plastidzeis as influenced by concentration and temperature. For example, in dibutyl sebacate, DBS, it is possible to observe high rates of PVC particles swelling at low temperatures, but at higher temperatures, at which fusion should already be completed, there are still PVC particles present, which were not affected by treatment. 

The differential scanning calorimetry, DSC, is usually employed to measure the glass transition temperature, Tg, of polymers. For PVC, the glass transition temperature is in the range of 80 to 90 °C, while for most plasticizers it is aroimd -100 to -60°C. 

For PVC-plasticizer mixtures, Nakajima attributed these intermediate transitions to the existence of at least three phases  

Along with the progress of gelation and fusion processes, the relative proportion of phases (1) and (3) diminishes wliile phase (2) increases. When the material is completely gelled and fused, only phase (2) exists, and so just one single glass transition temperature can be observed. 

Experiments carried out by Gomez-Ribelles et al with low proportions of plasticizer revealed that the Tg of pttre PVC can be spht irrto two different transition temperatures very close to each other. These authors concluded that in pure PVC there are two 

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This technique can be applied to samples prepared for study by scanning electron microscopy (SEM). When subject to impact by electrons, atoms emit characteristic X-ray line spectra, which are almost completely independent of the physical or chemical state of the specimen (Reed, 1973). To analyse samples, they are prepared as required for SEM, that is they are mounted on an appropriate holder, sputter coated to provide an electrically conductive surface, generally using gold, and then examined under high vacuum. The electron beam is focussed to impinge upon a selected spot on the surface of the specimen and the resulting X-ray spectrum is analysed. 

The morphologies of the tensile-fractured as-spun fibers and the flexural-fractured injection molded specimens were studied by scanning electron microscopy (SEM). 

The essential step is the efficient grinding and blending of raw materials. The final properties of cement strongly depend on its mineral composition so that raw composition and firing conditions are adjusted, depending on the type of cement to be produced. The microstructure of the steel fiber-cement paste interface was studied by scanning electron microscopy (SEM). The interfacial zone surrounding the fiber was found to be substantially different from the bulk paste further away from the fiber surface. The interfacial zone consisted of... 

The polymers chosen for the initial stages of our studies were poly-(methyl methacrylate) and polystyrene. There were several reasons for this choice, the most important being (1) well-characterized, low-molecular-weight monodisperse samples of poly(methyl methacrylate) and polystyrene are readily available, or at least relatively easy to synthesize and (2) the poly (methyl methacrylate) /polystyrene system is especially amenable to study by scanning electron microscopy, as we... 

Historical Silk Flags Studied by Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry... 

Murase, N. Echlin, P. Franks, F. The structural states of freeze-concentrated and freeze-dried phosphates studied by scanning electron-microscopy and differential scanning calorimetry. Cryobiology 1991, 28 (4), 364—375. 

The product of the interaction of chlorine gas with poly-DCH was studied by scanning electron microscopy (SEM) our SEM studies of pristine and brominated poly-DCH were previously rep>orted (lb). A sample at magnification 1500 is shown in Figure 1. Compared to pristine p>oly-DCH, Figure 1 reveals that a fibrous morphology is reUuned, but the fibers of the chlorinated polymer appear thicker and rougher than those of the reactant. 

Costello, M. L., Mathieu-Costello, O., and West, J. B. (1992). Stress failure of alveolar epithelial cells studied by scanning electron microscopy. Am. Rev. Respir. Dis. 145, 1446-1455. 

Analysis and spectroscopic study. The elemental analysis was performed with anICP-6000 spectrometer. The precursors crystallization was studied by thermal analysis methods (TG85). The samples were analysed by IR spectroscopy (Nicollet, FTIR-7500) and powder X-ray diffraction (PXRD, DRON-3). The morphology of surface was studied by scanning electron microscopy (SEM) (JEOL, JSM-6100). The density of KTP particles was determined by a sink-float method. Local x-ray analysis was performed using Link ISIS microanalysis system (Si Li detector) mounted on Jeol 2000 FX microscope. Bruker-400 apparatus was used for P, C and H NMR study of precursor solution. The YAG Nd SHG was measured on LS-10 device. 

Taking a step further, Kim et al. have studied the loading, release, and the preservation of bioactivity of a pol3rpep-tide, insulin, entrapped in a microbead formation. The morphology of the beads studied by scanning electron microscopy (SEM) revealed that they consisted of a dense skin layer and a porous inner structure. This suggested that the critical step of bead preparation is the formation of this skin layer or... 

Sinks BP, Kirkland M (2002) Interfacial structure of solid-stabilized emulsions studied by scanning electron microscopy. PCCP 4(15) 3727-3733... 

Wei Y, Xie C, Dean KA, Coll BF. Stability of carbon nanotubes under electric field studied by scanning electron microscopy. Appl Phys Lett 2001 79 4527-9. 

Further, a Zwick universal testing machine (Type 1474) served to measure the tensile modulus and tensile strength. This was carried out at room temperature and ambient conditions (approximately 50% humidity). The crosshead speed amounted to 1 mm/min. In addition, the broken samples were studied by scanning electron microscopy (SEM) (Jeol models JSM 5400 and JSM 6300). Thin films of dissolved samples were characterized by a Leitz transmission optical microscope. 

Copolymer resin (p-CAF) was synthesized by the condensation of p-cresol and adipamide with formaldehyde in the presence of hydrochloric acid as catalyst and using varied molar ratios of reacting monomers. A composition of the copolymers has been determined on the basis of their elemental analysis. The number average molecular weight of resins was determined by conductometric titration in non-aqueous medium. The copolymer resins were characterized by viscometric measurements in dimethylsulphoxide (DMSO), UV-visible absorption spectra in non-aqueous medium, infrared (IR) spectra, and nuclear magnetic resonance (NMR) spectra. The morphology of the copolymers was studied by scanning electron microscopy (SEM). 

The EDAX technique involves an analysis of the X-ray radiation emitted from surfaces which are studied by scanning electron microscopy (SEM). The surface studied by SEM is hit by the electron beam, emitting X-rays of a limited penetration depth which are specific to the elements present on the surface. This method provides qualitative and quantitative element analysis of electrode... 

SEM studies. The surface morphology of KL and KLd was studied by scanning electron microscopy (SEM) with a JEOL JSM-6400. The microscope was equipped with an energy dispersive X-ray (EDX) microanalyser that was used for observing the dispersion of the mineral matter in KL and KLd. 

Amend, X, Belitz, H.-D. The formation of dough and gluten - a study by scanning electron microscopy. Z. Lebensm. Unters. Forsch. 190, 401 (1990)... 

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