Small-angle X-ray

The X-ray instrumentation requires a commercial small angle X-ray camera, a standard fine structure X-ray generator and a sample manipulator if scanning is requested. The essential signal is the relative difference between the refraction level Ir and the absorption level Ia. Both levels are measured simultaneously by two scintillation detectors. At fixed angles of deflection this signal depends solely on the inner surface density factor C and thickness d of the sample [2] ... 

Brumberger H (ed) 1967 Small-Angle X-ray Scattering (New York Gordon and Breach)... 

Figure C2.17.12. Exciton energy shift witli particle size. The lowest exciton energy is measured by optical absorjDtion for a number of different CdSe nanocrystal samples, and plotted against tire mean nanocrystal radius. The mean particle radii have been detennined using eitlier small-angle x-ray scattering (open circles) or TEM (squares). The solid curve is tire predicted exciton energy from tire Bms fonnula.

Mattoussi H efa/1996 Characterization of CdSe nanocrystalline dispersions by small angle x-ray scattering J. Chem. Phys. 105 9890... 

O. Kiathy, in O. Glatter, O. Kiathy, eds., Small-Angle X-Ray Scattering, Academic Press, Inc., New York, 1982. 

Cazorla-Amords, D., dc Lecea, C. S. M., Alcaniz-Monge, J., Gardner, M., North, A. and Dore, J., Characterization of activated carbon fibers by small-angle x-ray scattering. Carbon, 1998, 36(3), 309 312. 

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. 

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. 

Cationic quaternary ammonium compounds such as distearyldimethylammonium-chloride (DSDMAC) used as a softener and as an antistatic, form hydrated particles in a dispersed phase having a similar structure to that of the multilayered liposomes or vesicles of phospholipids 77,79). This liposome-like structure could be made visible by electron microscopy using the freeze-fracture replica technique as shown by Okumura et al. 79). The concentric circles observed should be bimolecular lamellar layers with the sandwiched parts being the entrapped water. In addition, the longest spacings of the small angle X-ray diffraction pattern can be attributed to the inter-lamellar distances. These liposome structures are formed by the hydrated detergent not only in the gel state but also at relatively low concentrations. 

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],... 

Glatter D, Kratky O (1982) Small angle X-ray scattering, Academic, London... 

Using IR spectroscopy and NMR, one can analyze the chemical structure of PA. The molecular weight and molecular weight distribution can be analyzed by endgroup analysis, viscometry, and high-pressure liquid chromatography (HPLC). The crystalline order can be analyzed by WAXS, small-angle X-ray spectroscopy... 

Spectroscopy, 490. See also 13C NMR spectroscopy FT Raman spectroscopy Fourier transform infrared (FTIR) spectrometry H NMR spectroscopy Infrared (IR) spectroscopy Nuclear magnetic resonance (NMR) spectroscopy Positron annihilation lifetime spectroscopy (PALS) Positron annihilation spectroscopy (PAS) Raman spectroscopy Small-angle x-ray spectroscopy (SAXS) Ultraviolet spectroscopy Wide-angle x-ray spectroscopy (WAXS)... 

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