Method of small-angle X-ray

The method of small-angle X-ray scattering (SAXS) is known to be very sensitive to any type of structural heterogeneities in both dry and swollen polymers, and it was thought to give useful information on the structure of hypercrosslinked polystyrenes [199]. Figure 7.34 compares the... 

A change in conformation upon interaction with a hapten is indicated by the study of Pilz et al. (52a), who investigated the interaction of rabbit anti-poly-D-alanyl antibodies with tetra-D-alanine by the method of small-angle X-ray scattering. The interaction was associated with a significant contraction in volume (3-10%) and a small decrease in the radius of gyration of the antibody. The volume contraction was attributed to a conformational change. 

Ag dispersion was determined by various methods size of coherent scattering region (average size dv) was obtained by X-ray method surface average size ds - by adsorption method size distribution of Af particles was obtained by the method of small angle X-ray scattering (SAXS) and TEM. The two last methods were applied to determine the most probable size of Ag particles dp. 

Figure I. Schematic illustrations of microfocus synchrotron X-ray analysis methods (a) small-angle X-ray scattering (SAXS) (b) microfocus X-ray diffraction (XRD) and (c) microfocus X-ray fluorescence (XRF).

The progress in the determination of porosity of various types of materials has arisen over the past ten years from advances in application of new spectroscopy techniques. In the present paper the application of small angle X-ray scattering (SAXS), positronium annihilation lifetime spectroscopy (PALS) and low temperature nitrogen adsorption methods to the characterization of mesoporosity is reviewed using different types of silica gels with chemically modified surface. The results from the three methods are compared and discussed. 

Nafion has been the subject of extensive characterization studies [1]. Its microstructure has been exhaustively studied by scattering methods, especially small angle X-ray scattering (SAXS) and small angle neutron scattering (SANS) [19-23]. Mechanical properties of Nafion as functions of temperature have been used to identify temperature-induced transitions [2,24—27]. Transport of protons and water has also been the subject of numerous studies over the past 25 years [28-34]. However, there has been limited progress in coimecting the chemical structure of Nafion to mechanical and transport properties, especially how these properties are altered due to environmental conditions. In this chapter, we will review recent studies of mechanical and transport properties of Nafion done under controlled conditions of water activity and temperature. 

For the time being, a rigorous characterization and modehng of particle interactions is only possible for simple model systems A nice and very recent example is the measurement of the second viral coefficient and structure factor of quantum dots in solution by three independent methods, namely small-angle X-ray scattering (SAXS), cryo-TEM, and centrifugation (Van Rijssel et al, 2014). Nevertheless, the above-described approach can be transferred to many technical applications in a qualitative and conceptual way. 

Section 2 of this chapter describes the characterization of carbonaceous materials by powder X-ray diffraction, small-angle-X-ray scattering (SAXS), measurements of surface area, and by the carbon-hydrogen-nitrogen (CHN) test, a chemical analysis of composition. In this section, we also describe the electrochemical methods used to study carbonaceous materials. 

There are many ways to eharaeterize the strueture and properties of carbonaceous materials. Among these methods, powder X-ray diffraetion, small angle X-ray scattering, the BET surfaee area measurement, and the CHN test are most useful and are deseribed briefly here. To study lithium insertion in carbonaeeous materials, the eleetroehemieal lithium/earbon eoin eell is the most eonvenient test vehicle. 

In this case, the elements of the crosslinked structure exhibit higher mobility, the permeability of the crosslinked structure depends on the degree of hydration. It should be noted that the pore size in hydrated crosslinked copolymers is determined by small-angle X-ray scattering or with the aid of electron microscopy using special methods of preparation for the CP samples [15],... 

The thickness of the ordered crystalline regions, termed crystallite or lamellar thickness (Lc), is an important parameter for correlations with thermodynamic and physical properties. Lc and the distribution of lamellar thicknesses can be determined by different experimental methods, including thin-section TEM mentioned earlier, atomic force microscopy, small-angle X-ray scattering and analysis of the LAM in Raman spectroscopy. 

Application. Anomalous X-ray diffraction (AXRD), anomalous wide-angle X-ray scattering (AWAXS), and anomalous small-angle X-ray scattering (ASAXS) are scattering methods which are selective to chemical elements. The contrast of the selected element with respect to the other atoms in the material is enhanced. The phase problem of normal X-ray scattering can be resolved, and electron density maps can be computed. 

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