Interphase electron microscopy

QCMB RAM SBR SEI SEM SERS SFL SHE SLI SNIFTIRS quartz crystal microbalance rechargeable alkaline manganese dioxide-zinc styrene-butadiene rubber solid electrolyte interphase scanning electron microscopy surface enhanced Raman spectroscopy sulfolane-based electrolyte standard hydrogen electrode starter-light-ignition subtractively normalized interfacial Fourier transform infrared... 

Spontak R.J., Williams M.C., and Agard D.A., Interphase composition profile in SB/SBS block copolymers, measured with electron microscopy, and microstmctural implications. Macromolecules, 21, 1377, 1988. 

Lindner et al. carried out detailed studies on the use of the sol-gel procedure to obtain new materials as suitable matrices [45]. A co-condensation of Si(OR)4, Si(OR)3-spacer-Si(OR)3 and Si(OR)3-spacer-ligand resulted in new hybrid materials, the properties of which strongly depended upon the spacer and the ratio of the different components used. Most of these materials were characterised with IR, EXAFS, and EDX spectroscopy, scanning electron microscopy and solid state NMR spectroscopy. Solid state 31P NMR was used to quantify the mobility of the interphases the changes in line-... 

Several studies of polymer/silane coupling agent interphases have involved the use of scanning electron microscopy (SEM) [5-7]. For example, Vaughan and Peek [6] have used SEM to examine fracture surfaces to determine the mode of failure of composite materials and to draw conclusions about interfacial interactions of various coupling agents and epoxide and polymer resin systems. 

The uniformity of silane coatings was examined by scanning electron microscopy (SEM). SEM examination of the coated silanes showed a thin uniform coating to be present when a 0.5% silane aqueous solution was used. At higher silane concentrations, the coating was formed in lumps, which could clearly form a weak interphase when the fiber is embedded in the epoxy matrix. These observations are illustrated in Fig. 2. The formation of lumps of APS from a 5%... 

In this overview, we will first discuss how transmission electron microscopy (TEM) techniques can be used to determine the presence or absence of intergranular amorphous phases at interphase boundaries in structural... 

Interphase Interaction. Phase separation in this system is fairly complete, as demonstrated by both electron microscopy and the dynamic mechanical spectra. Nonetheless, interaction is consistent with the extent of separation of the tan 5 peaks, taken as a measure of Tg separation. Inspection of the data in the Tables shows that the greatest reduction in Tg separation occurs in the xx series, that there is some reduction in all series at the longest irradiation delay times, and that there is greater reduction with increasing proportions of PBMA in the mixtures. The changes with increasing delay time are fairly smooth. From the electron micrographs, total particle surface area and the proportion of fine particles increases with increased delay time in all series. 

Since the dimensions to be probed are of the order of few nanometers, the most useful microscopic method would be that of the transmission electron microscopy (TEM). Using this technique Fayt et al. [1986] observed location of P(S-b-HB) compatibilizer in a PE/PS blends. The authors inserted a short sequence of isoprene between the styrenic and hydrogenated butadiene blocks. After staining the isoprene double bonds with OsO, the authors were able to observe presence of the copolymer at the interface between the matrix and dispersed phase. Thickness of the interphase could then be measured. The experiments also demonstrated presence of the added compatibilizer as dispersed micelles inside the PE phase. This technique is applicable, however, only when selective staining affects only the compatibilizer. 

The scanning electron microscopy (SEM) revealed that both ternary and binary blends have a phase morphology typical of blend composites with active interphase interaction between polymer components. At equal concentrations of g-PO in blends, the ternary systems look more homogeneous than binary ones. It may be presumed. 

Zeolites form another class of materials useful for fundamental studies . As mentioned earlier, zeolites are microporous silica-aluminates with micropores of dimensions comparable to organic molecules. The materials are unique, because these micropores are determined by the three-dimensional crystallographic structure of the material and catalytic events occur at the interphase of zeolite micropore and zeolite lattice. As a result the catalytically active sites are well defined. Zeolites are used in practice in the acidic form or promoted with metal or sulfide particles. High Resolution Electron Microscopy, Neutron Diffraction and Solid State NMR are techniques that arc applied for structural characterization and to study the behaviour of chemisorbed molecules. 

Electron beam modification of PTFE nanopowder resulted in increasing concentration of radicals and carboxyhc groups (—COO H) with increase in irradiation dose. Low-temperature reactive mixing of the modified PTFE with ethylene-propylene-diene-monomer (EPDM) rubber produced PTFE coupled EPDM rubber compounds with the desired physical properties due to the formation of a compatible interphase this was confirmed by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) [56]. 

Two major techniques have been used to study the dimension of chromosome fibers by electron microscopy. The first is the surface spreading method, in which the cells are spread on a water-air interphase, and all the intracellular components are dispersed. But the chromatin and the spindle remain close together and can be picked up on a grid, which can then be prepared for electron microscopic examination. The second technique is the thin-sectioning method. After fixation the tissue is embedded in plastic and cut less than 1000 A thick. Refer to specialized texts for descriptions of these techniques [119]. The important finding is that with the first method, the dimension of the fibers diameter is estimated to be 200-300 A, whereas it is only 80-180 A with the second. 

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