X-ray scattering measurements

Phospholipid molecules form bilayer films or membranes about 5 nm in thickness as illustrated in Fig. XV-10. Vesicles or liposomes are closed bilayer shells in the 100-1000-nm size range formed on sonication of bilayer forming amphiphiles. Vesicles find use as controlled release and delivery vehicles in cosmetic lotions, agrochemicals, and, potentially, drugs. The advances in cryoelec-tron microscopy (see Section VIII-2A) in recent years have aided their characterization [70-72]. Additional light and x-ray scattering measurements reveal bilayer thickness and phase transitions [70, 71]. Differential thermal analysis... 

Polyetherimides show no crystallinity as evidenced from calorimetry measurements. The heteroarylene like phenylquinoxaline [27], oxadiazole [30], and benzoxa-zole [56] activated polyethers show TgS from DSC thermograms, with no evidence of crystallization, indicating amorphous or glassy morphology. Furthermore, wide angle x-ray scattering measurements show no evidence of crystalline or liquid crystalline type morphologies, consistent with an amorphous structure. F polyether... 

Small angle X-ray scattering measurements were performed using the synchrotron radiation of the DCI storage ring at LURE (Universite d Orsay,... 

It has been found by Will (2004) from X-ray scattering measurements that valence electrons concentrate along the lines connecting the boron atoms, confirming that the boron layer is a covalently bonded network. The titanium layers are metallic. However, the layers are not characteristic of either pure Ti, or pure B, so the bonding is quite complex. 

For very large R the behavior of koo R) is determined by long wavelength density fluctuations, hence by the compressibility of the liquid. Precision small angle X-ray scattering measurements 17>, as well as extrapolations of hoo(s) to s = 0 for the data shown, are in agreement with predictions based on bulk thermodynamic data. 

Finally, in x-ray diffraction measurements the knowledge of the equation of state (EOS) of specific materials is used to calculate the pressure by the measurement of selected reflections. For this purpose, Au [266], NaCl [267], Re [268], Pt [269], and MgO [231] have been used in x-ray scattering measurements when no optical access was available. 

Solution calorimetry, 24 11-15 in bromine ttifluoride, 24 12-14 in fluorosulfuric acid, 24 11-12 in water, 24 14-15 Solution-phase reactive intermediates flow systems, 46 159-160 low temperature, 46 131-136 Solution X-ray scattering measurements, transferring, 41 409-410 Solvation, ionic, 21 211-213 Solvents... 

Aqueous solutions of molybdate and arsenate, pH 3-5, contain [AsMo903i(H20)3]3 and an As2Mo6 anion.71 The exact structure of the latter ion in solution is in some doubt, although the tetramethylammonium sodium salt contains the anion shown in Figure 15. Low angle X-ray scattering measurements of aqueous molybdoarsenate solutions are not compatible with this structure and the anion may be hydrated in a fashion similar to that observed for the analogous... 

Small-Angle X-Ray Scattering Measurements of Biopolymer Molecular Weights in Interacting Systems... 

Thus, in small-angle x-ray scattering, measurement of the molecular weight of a macromolecule in concentrated solvent requires knowledge of the preferential interaction parameter. This can be measured by techniques such as differential refractometry, densimetry, and isopiestic vapor phase equilibrium measurements. For densimetry,... 

The inelastic X-Ray scattering measurements [12] demonstrated a weak dispersion branch between 60 and 70 meV in the TA direction with E29 symmetry at the T point. The linewidth of this mode is about 20-j-28 meV along the TA direction, while along the TM direction it is below the experimental resolution. This points to the very strong electron-phonon interaction (EPI) for this particular lattice vibration mode. 

H Bomsdorf, T Mueller and H Strecker (2004) Quantitative simulation of coherent x-ray scatter measurements on bulk objects. J. X-ray Sci. Technol. 12, 83-96. 

SAXS (Small Angle X-ray Scattering) measurements provided further insight into the structure of the assembly in solution [70]. Using the GNOMN/DAMMIN software packages, the SAXS data were used to reconstruct a low resolution three-dimensional particle shape (yellow semitransparent spheres in Fig. 19) [71-74]. 

---