WAXS studies

R. White, The application of gas chromatography to the identification of waxes, Studies in... 

Violante A, Krishnamurti GSR, Pigna M (2008) Mobility of trace elements in soil environments. In Violante A, Huang PM and Gadd G (eds) Wiley-JUPAC series on biophysico-chemical processes of metals and metalloids in soil environments. John Wiley Sons, Hoboken, USA Waltham AC, Eick MJ (2002) Kinetic of arsenic adsorption on goethite in the presence of sorbed silicic acid. Soil Sci Soc Am J 66 818-825 Waychunas GA, Fuller CC, Rea BA, Davis J (1996) Wide angle X-ray scattering (WAXS) study of two-line ferrihydrite structure Effect of arsenate sorption and counterion variation and comparison with EXAFS results. Geochim Cos-mochim Acta 60 1765-1781... 

Composition B Wax Study , Annual Mtg, Loading Section, Ammo Technol Div, American Defense Preparadness Assn (1974) 93) W. Bren-... 

Waychunas, G.A., Fuller, C.C., Rea, B.A. and Davis, J.A. (1996) Wide angle X-ray scattering (WAXS) study of two-line ferrihydrite structure effect of arsenate sorption and counterion variation and comparison with EXAFS results. Geochimica et Cosmochimica Acta, 60(10), 1765-81. 

A similar organized solvent mantle is proposed to be present around the silicate species and a displacement of the hydration mantle around the SDA by the silicate species is the origin of the SDA-silicate interaction. Long-range order is attained in a consecutive layer-by-layer zeolite growth step. This proposed formation mechanism is in agreement with results of an in situ SAXS and WAXS study by de Moor et a//151 of the same system. Their results show the initial formation of colloidal... 

WAXS studies of both relatively amorphous (51,53) and crystalline (56) samples of the symmetrically substituted polymers 15 (R = R = Me, Et) have been reported. The WAXS patterns for unnannealed samples of 15 (R = R = Me, Et) show broad lines superimposed on amorphous halos, which suggest the presence of only short-range order (51,53). More crystalline samples of these polymers show several sharper lines consistent with the presence of significant long-range order (56). Interestingly, the WAXS pattern of 15 (R = R = n-Bu) shows several fairly sharp peaks indicative of substantial order, whereas that of 15 (R = R = -Hex) shows only typical amorphous halos (51,53,56). 

Casanove M-J, Lecante P, Snoeck E, Mosset A, Roucau C (1997) HREM and WAXS study of the structure of metallic nanoparticles. J Physique III 7 505-515... 

Recent studies in the fine structures of radiation polymerized PTOX show that they are disordered crystals in which maln-crystal-lites and sub-crystallites are arranged in series (7)- The fine structures of PTEOX are even more disordered and complex than those of PTOX, and are believed to possess an oriented lamellar morphology. However, when the post-polymerization is carried out at temperatures above 90 C, the sub-crystallites disappear. WAXS studies indicate that the (009) and (0018) reflections of PTEOX have an asymmetrical profile, suggesting the existence of two different lattice spacings along the fiber axis. Odajima, et al. (8) suggested that there may be two kinds of crystallites present, namely those with the extended fibrillar and the folded lamellar morphologies. 

Wide-angle X-ray scattering (WAXS) studies of PL-LA revealed the existence of two crystalline modifications. De Santis [21] described the structure of the a crystalline modification as pseudoorthorhombic with the chains in a 10/3 left-handed helix. Hoogsteen [22] reported a P orthorhombic crystal structure, characterized by a 3/1 left-handed helical conformation. 

Figure 4.21 shows a focal-conic fan texture of a smectic A phase in which is observable some defects represented by Figure 4.20(b). While Sa forms the fan-like focal-conic textures, the focal-conics formed by the Sc phase are often broken and less distinct. In addition, as stated above, Sa is uniaxial but Sc is biaxial. Sa may take a homeotropic alignment with the axis normal to the sample plane and extinct on POM with crossed polars. The two smectic phases are therefore distinguishable with POM. Nevertheless, it is desirable to include WAXS studies in order to identify the two with assurance (Section 4.3). 

SAXS/WAXS studies of synthetic or biological fibrils in the pm-range and less, or complex morphological structures encountered in processed polymer foils. 

Shaw S, Henderson CMB, Komanschek BU (2000b) Dehydration/reciystallization mechanisms, energetics, and kinetics of hydrated calcium silicate minerals an in situ TGA/DSC and synchrotron radiation SAXS/WAXS study. Chem Geol 167 141-159... 

F. Dassenoy, K. Philippot, T. Ould-Ely, C. Amiens, P. Lecante, E. Snoeck, A. Mosset, M. J. Casanove, and B. Chaudret. Platinum nanoparticles stabilized by CO and octanethiol ligands or polymers FT-IR, NMR, HREM and WAXS studies. New J. Chem., 22 703-711, 1998... 

The experimental arrangement used for WAXS studies of polymers depends on the purpose of the studies and will be discussed in the appropriate later chapters. These studies include the determination of crystal structure, the determination of crystallinity and studies of molecular orientation, among others. 

Fig. 17 Kinetic WAXS study of the stretch-induced isotropic-mesophase transition in cross-linked PDES (after Koerner et al. [174])...

SAXS and wide angle X-ray scattering (WAXS) studies were carried out to... 

WAXS studies were also performed on polymer fibers from SMPU with SME [61] to investigate structural differences between bulk material (SMPU) and spun fibers (SMF). It could be shown that the degree of crystallinity of a certain SMF was higher than that of the corresponding SMPU. In this way, it was verified that the spinning process could prompt the formation of hard domain crystallites. In the same study SAXS experiments were also performed to investigate the SMP structure on the next higher level of hierarchy. 

WAXS studies on the structure of sono-aerogels established that the atomic sonogel stmcture is very cross-linked. Figure 20.10 represents the sonogel and silica glass reduced RDF,... 

M. Fujita, T. Sawayanagi, T. Tanaka, et aL, Synchrotron SAXS and WAXS studies on changes in structural and thermal properties of poly[(R)-3-hydroxybutyrate] single crystals during heating, Macromol. Rapid Commun., 26 (2005) 678-683. 

In conclusion of the melting behavior of PTeOX, the endothamic profiles of PTeOX prepared below 90 °C is different from that prepared above 90 °C. From the results of the X-ray diffraction, mentioned in Section 2, can be seen that the polymerization of T OX in the solid state produces the main and sub-crystals below 90 °C, while the main crystal and a aystal corresponding to 100 A scattering in SAXS are formed above 90 °C. Chatani et al. used PT OX prepared at 62 C to show main and sub-crystals from WAXS study, and Amano et al. used PTeOX prepared at 100 °C to w only lamellar type crystals from SAXS and EM studies. Both results seem to be somewhat similar, but we can not compare their data since the characteristics of PTeOX prepared at different temperatures are different. PTeOX prepared at 100 °C contains the main crystals beside lamellar type crystals as mentioned later. 

According to the WAXS studies, after extrusion, the bristles are distinguished by a rather isotropic structure. Figure 11.3(a) is typical for a semicrystalline polymer crystallized in a completely isotropic state. As a matter of fact, this WAXS pattern is talcen from the extruded sample after the melt blending. It must be noted that the same conclusion was drawn from the SEM observation of the same sample (Figure 11.2(a)). It is important to note that although the extrudate has the shape of a bristle (the same as that after drawing), any preferred orientation is absent. This means that the shape of... 

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