Complementary techniques film studies

Fluorescence Of Monolayers Containing Pyrene-Labeled Probes. A fluorescence probe method was also used as a complementary technique to study the thermodynamics of SA film formation. Mixed monolayers containing the fluorescence probe pyrene hexadecanoic acid, Py-C16, in host fatty acids of different lengths were prepared by adsoiption from solutions containing mostly the host fatty acid and a small fraction of Py-C16 (approximately 1 to 5 mol %). All monolayers were prepared under equilibrium adsoiption conditions. For fluorescence measurements only A1 substrate was used because when glass is used an impurity fluorescence from glass interferes with the pyrene fluorescence. 

Absorption Spectroscopy. - UV-visible spectroscopy was mainly used as a complementary technique in structure elucidation, particularly (with FTIR) for following the photooxidation under accelerated conditions of poly[bis(4-isopro-pylphenoxy)phosphazene], and in the characterisation of Langmuir and Lang-muir-Blodgett films of diphenylbis(octadecylamino)phosphonium bromide. Specifically, a UV-visible spectral study of several a-propylamino-phosphonic acid methyl esters (55) has been undertaken. 

NEXAFS is a synchrotron-based spectroscopic tool routinely used as a complementary technique with XPS for surface characterizations. This method probes the adsorption of X-rays by the excitation of core (K-shell) electrons into unoccupied electronic states near the ionization limit. Subsequent emission of Auger electrons results in the formation of an NEXAFS electron yield the observed spectmm. Because the source of Auger electrons can extend only up to 10 nm and the spectral peak positions and intensities are directly related to the nature of unoccupied electronic states, NEXAFS spectroscopy provides an important tool for studying stmctural and chemical features of various surface thin films and coatings (Hemraj-Benny et al., 2006 Hahner, 2006). 

Surface conductance is not a spectroscopic technique at all but is included here as it is in many ways complementary to optical studies, and the theoretical treatment has much in common with reflectance theory. Experimentally the conductivity of a thin film electrode (typically 5-50 nm) is measured as a function of an electrochemical variable such as potential (in fact modulation... 

Complementary microscopic techniques are useful in the elucidation of polymer film microstructures. Optical techniques provide information relating to the orientation and crystallinity, while SEM can be used for surface detail relevant to end uses. TEM techniques, similar to those used in model film studies and in fibers, are useful in describing the internal structures, especially of spherulites and their deformed counterparts, microfibrils. TEM studies of films and fibers continue to provide fundamental observations relating the structure to properties and applications. 

A major topic of interest relating to film structure is the effect of crystallinity on the deformation mechanism. The optical properties of biaxially oriented films were studied in 1957 by Stein [109] who determined the full set ofbirefrin-gences, by measuring the optical retardation as a function of the tilt of a PS film. Samuels [110] used complementary techniques of x-ray scattering, TEM of surface replicas and birefringence measurement in a study of the microstructure... 

We have presented a series of experiments developed to understand the spreading behaviour of small drops of nonvolatile liquid deposited on smooth solid surfaces. Several complementary techniques have been used to completely characterize the drop profile at all length scales. We have paid special attention to the thin precursor film which develops all around the drop, first because precursor film studies on well-controlled systems are not numerous, and second, because this precursor film is of fundamental importance to understand the role of long-range forces on spreading. 

Complementary techniques used in electrochemical studies of fullerene films... 

The rapid development of solid state physics and technology during the last fifteen years has resulted in intensive studies of the application of plasma to thin film preparation and crystal growth The subjects included the use of the well known sputtering technique, chemical vapour deposition ( CVD ) of the solid in the plasma, as well as the direct oxidation and nitridation of solid surfaces by the plasma. The latter process, called plasma anodization 10, has found application in the preparation of thin oxide films of metals and semiconductors. One interesting use of this technique is the fabrication of complementary MOS devices11. Thin films of oxides, nitrides and organic polymers can also be prepared by plasma CVD. 

During the past 14 years, intensive work has been devoted to the study of surface film formation on noble metals in nonaqueous Li salt solutions using surface sensitive techniques. The major goal of this work had been to analyze the surface species formed at different potentials on nonactive electrode surfaces as a function of solution composition. The most successful tool has been ex situ and in situ FTIR spectroscopy [3,4,6,7,16,17], However, other techniques such as Raman [32,33], XPS [12], and EDAX have also been applied. These systems have also been studied in parallel by impedance spectroscopy [34] and EQCM [35], These measurements are complementary to the voltammetric studies de-... 

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