Useful Characterization Methods

There are many ways to characterize the structure and properties of carbonaceous materials. Among these methods, powder X-ray diffraction, small angle X-ray scattering, the BET surface area measurement, and the CHN test are most useful and are described briefly here. To study lithium insertion in carbonaceous materials, the electrochemical lithium/carbon coin cell is the most convenient test vehicle. 

Carbon samples used for powder X-ray diffraction were obtained by grinding the as-made carbons. If carbon samples are supplied in powder form, they can be measured directly. The powder consists of an enormous number of ten-micron-sized particles usually with completely random orientation. 

2 Scherrer equation to estimate the size of organized regions Imperfections in the crystal, such as particle size, strains, faults, etc, affect the X-ray diffraction pattern. The effect of particle size on the diffraction pattern is one of the simplest cases and the first treatment of particle size broadening was made by Scherrer in 1918 [16]. A more exact derivation by Warren showed that, 

In this chapter, the structure refinement program will be used to determine the structural parameters of graphitic carbons as shown in section 3. 

Small-angle X-ray scattering (SAXS) [19] has been widely used to investigate the inhomogeneous electron density in materials [20]. In carbonaceous materials, porosity is commonly encountered. The pores form and provide escape routes for gases produced during the pyrolysis process. 

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Gas adsorption (physisorption) is one of the most frequently used characterization methods for micro- and mesoporous materials. It provides information on the pore volume, the specific surface area, the pore size distribution, and heat of adsorption of a given material. The basic principle of the methods is simple interaction of molecules in a gas phase (adsorptive) with the surface of a sohd phase (adsorbent). Owing to van der Waals (London) forces, a film of adsorbed molecules (adsorbate) forms on the surface of the solid upon incremental increase of the partial pressure of the gas. The amount of gas molecules that are adsorbed by the solid is detected. This allows the analysis of surface and pore properties. Knowing the space occupied by one adsorbed molecule, Ag, and the number of gas molecules in the adsorbed layer next to the surface of the solid, (monolayer capacity of a given mass of adsorbent) allows for the calculation of the specific surface area, As, of the solid by simply multiplying the number of the adsorbed molecules per weight unit of solid with the space required by one gas molecule ... 

Electrical measurements are among the most ancient methods used to characterize samples at high pressures. Indeed, before the advent of diamond-anvil cells (DACs), they were the most often used characterization methods in belt-type or multianvil devices at pressures above 2 GPa for the detection of solid-solid phase transitions—upon which the so-called fixed-point pressure scale was based (see Section 2.2 in Chapter 2). 

The distinguished career of Professor Paul H. Emmett has spanned six decades, beginning with his Ph.D. research under A.F. Benton at the California Institute of Technology in 1922. His pioneering contributions to the field of catalysis have provided the foundation for much of the present-day work in the field. Among his most notable contributions is the BET method for determining the surface area of solids, done in collaboration with Stephen Brunauer and Edward Teller. Surface area measurement by the BET method is probably the most widely used characterization method in catalysis today. 

FTIR is a powerful and useful characterization method for polymers, and materials in general. This is an economic, short time characterization that allows to establish the chemical composition, microstructure, chemical interactions and even to follow variation of specific functional groups with time, during reactions. 

In this chapter, we briefly review the basic synthesis routes of SMOs, the various surface structures that can arise and their correlations to surface density ranges, and the commonly used characterization methods for SMOs. We discuss the difference between surface saturation and monolayer (ML) coverage, two terms that represent different surface density thresholds but can be confused with one another. We analyze the different surface density calculation methods used, which can lead to numerical discrepancies that complicate investigations into structure-property relationships for SMOs. We discuss the most appropriate calculation method, using mngstated zirconia (WO /ZrOj) prepared through incipient wetness impregnation as the model SMO material. 

The topics discussed in this chapter are divided into three sections physical characterization, chemical analysis, and the characterization of biointerfacial events. In each section, the principles behind the most commonly used characterization methods are presented, the techniques are described, and typical measurements are illustrated with examples. The emphasis is on methods to quantify and characterize protein adsorption on thin films, which precedes host biological responses. 

In recent development of the semiconductor industries, thermal oxide film thickness of less than 5 nm has been used in semiconductor devices such as metal-oxide-semiconductor (MOS) structures. Thickness of less than 5 nm is almost near the thickness of a native oxide film on the surface of silicon wafer. Therefore the characterization of ultra thin native oxide film is important in the semiconductor process technology. The secondary electron microscopy (SEM), the scanning Auger electron microscopy (SAM), the atomic force microscopy (AFM) and the X-ray photoelectron spectroscopy (XPS) might be the useful characterization method for the surface of the silicon wafers. 

The most useful characterization method was C NMR which generally allowed separation and identification of all unique carbons in the repeat units. Figures 2-4 illustrate this for... 

The fundamental properties of materials such as optical contrast, coloration efficiency, switching speed, stability and optical memory are the commonly used characterization methods to decide the type of materials to be used for application purposes. The transport dynamics of intercalating... 

There are a number of useful characterization methods that make use of XRD and scattering techniques [13]. The typical wavelength used for X-ray studies is -0.15 nm, a wavelength about the dimension of the carbon-carbon bond. Based on the diffraction theory, the X-ray methods can probe the presence of structures as small as this bond distance, making X-ray methods ideal for studying organization of polymers. This section briefly describes these techniques and provides a description of the information that can be provided by using these methods. They include XRD (powder and... 

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