Interference microscopy investigation

By measuring diffusivities at several temperatures, an activation energy for diffusion of 22.6 kj/mol was derived. Extrapolating the NSE diffusivities to 300 K, one obtains a value of 8 x 10 m s , which is in good agreement with an interference microscopy investigation performed on the same system which gave 1 x 10 j 2 g-i [45] example shows the potential of the NSE technique to study the diffusion of more complex branched alkanes in silicahte. 

While electron or ion beam techniques can only be applied under ultra-high vacuum, optical techniques have no specific requirements concerning sample environment and are generally easier to use. The surface information which can be obtained is, however, quite different and mostly does not contain direct chemical information. While with infra-red attenuated total reflection spectroscopy (IR-ATR) a deep surface area with a typical depth of some micrometers is investigated, other techniques like phase-measurement interference microscopy (PMIM) have, due to interference effects, a much better surface sensitivity. PMIM is a very quick technique for surface roughness and homogeneity inspection with subnanometer resolution. 

Interference microscopy as a tool of choice for investigating the role of crystal morphology in diffusion studies... 

In addition to mixtures of single-chained anionic and cationic surfactants, mixtures of single-chained anionic surfactants with double-chained cationic surfactants have also been studied. The phase equilibria of the SDS-DDAB-water system have been studied by water deuteron nuclear magnetic resonance (NMR) and polarization microscopy methods at 40°C [27]. Based on particle size measurements, the possibility of vesicle formation has been realized from this study. Spontaneous vesicle formation in the aqueous mixture of didodecyldimethylammonium bromide and sodium dodecyl sulfate has been investigated with differential interference microscopy, transmission electron microscopy, glucose-trapping experiments, -potential measurements, and surface-tension measurements [28]. A solution of DDAB with a small amotmt of SDS is a lamellar phase. Adding more SDS induces surfactant precipitation. Further addition of SDS causes DDAB-SDS precipitate to disperse and results in the vesicle formation. The DDAB and SDS mixtures yield... 

The phenomenon of the loading and breakdown of the molecular strands has been studied by various methods. Optical and electron micrographs of crazes are shown in most of the cited references. Examples have been reproduced in Figures 9.8—9.10. Investigations of the craze shape by interference microscopy [15,155, 177] have also been discussed. At this point some results will be reported which have been obtained by thermal measurements [31, 50, 184—186], from analysis of the influence of molecular weight on crazing [11,15,65, 79, 146,178], through acoustic emission [174, 188], and by the ESR technique [189—190] respectively. 

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