Surface characterization and analysis

Membrane surface characterization and analysis indicated that significant elemental and oxidative changes occurred on the membrane surface upon heating, and again after flux testing. In particular, XPS indicated that metallic Ni migrated or otherwise appeared at... 

X-ray photoelectron spectroscopy (XPS) is widely used for surface characterization and analysis of polymers, biomedical materials and paper. The technique was developed by Kai Siegbahn in the 1960s, who realized that technical development had come to a point where the photoelectric effect discovered by Einstein could be used for surface chemical analysis. The photoelectric effect is the phenomenon that occurs when a material is exposed to photons with sufficiently high energy and electrons contained in the material with a lower binding energy are emitted. Therefore, we can write ... 

The first three chapters discuss definitions, adhesion theories, surface characterization and analysis, surface energy measurement methods, adhesion mechanism, failure modes, and surface treatment of materials. 

The scanning electron microscope (SEM) has been shown to be an effective instrument for the analysis of physical evidence materials. Both topographical, i.e. surface characterization, and compositional, i.e. elemental constitution, analyses have been successfully reported in several recent studies (l—8). The utilization of this instrumentation has widely increased. 

A considerable amount of work has been published during the past 20 years on a wide variety of emulsion polymerization and latex problems. A list of 11, mostly recent, general reference books is included at the end of this chapter. Areas in which significant advances have been reported include reaction mechanisms and kinetics, latex characterization and analysis, copolymerization and particle morphology control, reactor mathematical modeling, control of adsorbed and bound surface groups, particle size control reactor parameters. Readers who are interested in a more in-depth study of emulsion polymerization will find extensive literature sources. 

Spadavecchia J., Ciccarella G., and Rella R., Optical characterization and analysis of the gas/surface adsorption phenomena on phthalocyanines thin films for gas sensing application. Sens. Actuators B, 106, 212-220, 2005. 

S.M. Martin, R. Ganapathy, T.K. Kim, D. Leach-Scampavia, C.M. Giachelli, B.D. Ratner, Characterization and analysis of osteopon-tin-inunobilized poly (2-hydroxyethyl methacrylate) surfaces, J. Biomed. Mater. Res. A 67 (2003) 334-343. 

Early studies on PLLA mainly focused on the identification of characteristic bands to investigate the polymer crystallinity. Since Fourier transform infrared (FUR) spectroscopy is sensitive to the conformation and local molecular environment, this technique has also been used to elucidate the structure of the crystalline polymers. More recently, research on PLLA surface characterization using FTIR has been an object of interest. This section is divided into three parts structural analysis, surface characterization, and crystallization studies. 

Characterization and analysis are performed using the following surface science techniques temperature programmed desorption/reaction (TPD/TPR), pulsed molecular beam reactive scattering (pMBRS) (IRRAS), metastable impact electron spectroscopy (MIES), ultraviolet photoelectron spectroscopy (UPS) and auger electron spectroscopy (AES). First the experimental setup is briefly described, followed by the support preparation and characterization as well procedures utilized in this work. These descriptions include a concise introduction to the underlying physical principles of the applied techniques (including experimental details). 

Based on the characterization and analysis of the worn surfaces, it has been proposed that the anti-wear mechanism consists of the prepared compound boron-containing thiophosphite derivative reacting with the steel surface during the friction process to generate a protective film mainly composed of phosphate, sulfide, sulfate, organic amine, and B2O3 (25). 

Technical processes that employ ionizing radiation are widely applied in the polymer field, and include the production of crosslinked wire insulation and of heat-shrink food wrappings and tubings for electrical connections, the vulcanization of rubber tires and rubber lattices, and the curing of coatings and inks. Moreover, various X-ray methods can also be appUed for the characterization and analysis of polymers, especially of the polymer surfaces. Both, X-ray imaging and X-ray microscopy allow the derivation of quantitative composition maps of polymer surfaces. Notable in this context are also near-edge X-ray absorption fine structure spectroscopy (NEXAFS), extended X-ray absorption fine structure spectroscopy (EXAFS) and X-ray photoelectron spectroscopy (XPS). 

The external reflection of infrared radiation can be used to characterize the thickness and orientation of adsorbates on metal surfaces. Buontempo and Rice [153-155] have recently extended this technique to molecules at dielectric surfaces, including Langmuir monolayers at the air-water interface. Analysis of the dichroic ratio, the ratio of reflectivity parallel to the plane of incidence (p-polarization) to that perpendicular to it (.r-polarization) allows evaluation of the molecular orientation in terms of a tilt angle and rotation around the backbone [153]. An example of the p-polarized reflection spectrum for stearyl alcohol is shown in Fig. IV-13. Unfortunately, quantitative analysis of the experimental measurements of the antisymmetric CH2 stretch for heneicosanol [153,155] stearly alcohol [154] and tetracosanoic [156] monolayers is made difflcult by the scatter in the IR peak heights. 

Photoelectrochemistry may be used as an in situ teclmique for the characterization of surface films fonned on metal electrodes during corrosion. Analysis of the spectra allows the identification of semiconductor surface phases and the characterization of their thickness and electronic properties. 

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