Composite surface morphology

The composition, surface morphology, and appearance of Zn-Co alloy deposits were studied as a function of experimental conditions [431 -435]. These alloys were also found to be more corrosion resistant than zinc but less resistant than cobalt [432]. 

The chemical composition, surface morphology, electrical conductivity, optical absorption, and Li-ion conductivity have been investigated. It is found that in... 

Dual sputtering deposition technique was used to prepare submicron thin Pd-Cu alloy films, which allowed a high composition control of the layer (Hoang et al, 2004). The composition, surface morphology and phase structure of the sputtered layers were investigated by EDS, X-ray, XPS, SEM, TEM and XRD. For example, the XRD data proved that the Pd-Cu layers were an alloy of Pd and Cu. Subsequently, the characterized Pd-Cu alloy layers were deposited on a silicon support structure to create a 750 nm thin Pd-Cu membrane for H2 separation. The reported membrane obtained a high H2 flux of 1.6 moF(m s) at a temperature of452°C, while the selectivity was at least 500 for H2/He. 

Detemiining compositions is possible if the distribution of elements over the outer layers of the sample and the surface morphology is known. Two limiting cases are considered, namely a homogeneous composition tliroughout the outer layers and an arrangement in which one element covers the other. 

In a molded polymer blend, the surface morphology results from variations in composition between the surface and the bulk. Static SIMS was used to semiquan-titatively provide information on the surface chemistry on a polycarbonate (PC)/polybutylene terephthalate (PBT) blend. Samples of pure PC, pure PBT, and PC/PBT blends of known composition were prepared and analyzed using static SIMS. Fn ment peaks characteristic of the PC and PBT materials were identified. By measuring the SIMS intensities of these characteristic peaks from the PC/PBT blends, a typical working curve between secondary ion intensity and polymer blend composition was determined. A static SIMS analysis of the extruded surface of a blended polymer was performed. The peak intensities could then be compared with the known samples in the working curve to provide information about the relative amounts of PC and PBT on the actual surface. 

The chemical composition of the SEI formed on carbonaceous anodes is, in general, similar to that formed on metallic lithium or inert electrodes. However some differences are expected as a result of the variety of chemical compositions and morphologies of carbon surfaces, each of which can affect the i() value for the various reduction reactions differently. Another factor, when dealing with graphite, is solvent co-intercalation. Assuming Li2C03 to be a major SEI building material, the thickness of the SEI was estimated to be about 45 A [711. 

The SEI is formed by parallel and competing reduction reactions and its composition thus depends on i0, t], and the concentrations of each of the electroactive materials. For carbon anodes, (0 also depends on the surface properties of the electrode (ash content, surface chemistry, and surface morphology). Thus, SEI composition on the basal plane is different from that on the cross—section planes. 

Surface composition and morphology of copolymeric systems and blends are usually studied by contact angle (wettability) and surface tension measurements and more recently by x-ray photoelectron spectroscopy (XPS or ESCA). Other techniques that are also used include surface sensitive FT-IR (e.g., Attenuated Total Reflectance, ATR, and Diffuse Reflectance, DR) and EDAX. Due to the nature of each of these techniques, they provide information on varying surface thicknesses, ranging from 5 to 50 A (contact angle and ESCA) to 20,000-30,000 A (ATR-IR and EDAX). Therefore, they can be used together to complement each other in studying the depth profiles of polymer surfaces. 

CO in the synthesis gas mixture for the methanol synthesis does not seem to take part directly in the reaction, but it does influence the process through two effects First the water-gas shift reaction and, secondly, through its effect on the surface morphology (and possibly also composition). For thermodynamic reasons, however, it would be desirable if CO could be hydrogenated directly via Eq (18) instead of going through two coupled equations (3) and (19), since it would yield a higher equilibrium concentration of methanol at the reactor exit. 

Recent developments have allowed for more detailed studies of polymer surface morphology by ESCA. Angle-resolved ESCA (ARXPS) allows for providing chemical compositions from shallower depths. By varying the angle of incidence different depths can be probed, and procedures have been developed to arrive at three-dimensional reconstruction of the surface. An example is shown in Figure 2, where a PVC/PMMA polymer blend has been analysed using such an approach [9]. 

Figure 17. The basal plane and prismatic surfaces of graphite have different functions with respect to lithium intercalation and de-intercalation (= charge, discharge, self-discharge, etc.). As a consequence, only the electrolyte decomposition product layers at the prismatic surfaces have SEIfunction. Any processes related with electrolyte decomposition product layers at the basal plane surfaces (= non-SEI layers) therefore can not be directly related to electrochemical data such as charge, discharge, self-discharge, etc. The situation is even more complex as the SEI composition and morphology at the basal and prismatic surface...

Lodi, G., Sivieri, E., Debattisti, A., and Trasatti, S., Ruthenium dioxide-based film electrodes. III. Effect of chemical composition and surface morphology on oxygen evolution in acid solutions, /. Appl. Electrochem., 8, 135, 1978. 

Global characterisation of the nucleus and determination of dynamic properties, surface morphology and composition. 

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