SANS scattering

The experimental techniques for the study of conformational branched properties in solution are the same as used for linear chains. These are, in particular, static and dynamic light scattering, small angle X-ray (SAXS) and small angle neutron (SANS) scattering methods, and common capillary viscometry. These methods are supported by osmotic pressure measurements and, nowadays extensively applied, size exclusion chromatography (SEC) in on-line combination with several detectors. These measurements result in a list of molecular parameters which are given in Table 1. 

Fourier-transform infrared (FT-IR) spectroscopy and small-angle X-ray (SAXS) and neutron (SANS) scattering studies have shown the existence of a further pressure induced gel phase in DPPC bilayers." " Pressure dependent NMR studies yielded complementary information on the pressure-induced gel phases. The gel state of DPPC bilayers shows a variation in lineshapes which depend on the particular pressure and temperature. The types of lineshapes seen in a high pressure investigation of dg2-DPPC by Jonas et al. are... 

Figures 6.2 and 6.3 compare the SANS scattering responses, for RH=0.11 and RH=0.87, of the dry carbon, the carbon+TD, carbon+0 0, and carbon + D O+TD. The loss of intensity due to the reduced contrast factor is evident in the region 0.2A

Figure 5. SANS scattering curve i(q) vs. q of a G3-dendronized polystyrene, obtained by Forster, Schluter et al. [25], The scattering curve at larger q follows the Porod q law, arising from the scattering at the surface of a cylinder, evidencing the stiff, worm-like character of the macromolecules.

Fig.9 SAN scattering curves of aqueous solutions at three different PDADMAC concentrations above the critical overlap concentration, c, without additional salt. The polymer concentration is given in monomol IT1 MW(PDADMAC)=100,000 g mol1 (from Ref. [42])...

Table 1. Calculation of SAXS and SANS-scattering length densities for polymers ...

Figure 3. S AXS and SANS scattering intensities for a Si02 PDMS composiie thought be be bicontinuous, shown as a function of the scattering vector (in reciprocal A). The numbers attached to the two curves give values of the terminal slope, which is of interest with reg to charactoizing the interfaces.

In the extensive contrast-variation study [115] about 720 separate measurements in total were performed for the decane and hexadecane systems. The ten contrasts that these correspond to for each system were then fitted simultaneously to obtain the size distribution and the average shape of the microemulsion droplets. Some of the SANS scattering curves and their fits are presented in Figure 3.13. 

Fig. 2.10 SANS scattering from a fiiUy hydrogenous PU before (solid bne) and after straining to 3(X)%, with data in the ptiraUel (open circles) and perpendicular (solid circles) to the draw direction.

The SANS scattering function, which is analogous to the structure factor (O Eq. (29.21)), can be written as follows ... 

The most used techniques for characterizing the internal nanostructures of aqueous dispersions of LLC phases are the small angle X-ray (SAXS) and neutron (SANS) scattering techniques. Figure 2 (left) shows the typical SAXS patterns for the fully hydrated non-dispersed V2, H2, and L2 bulk phases (black lines) and their corresponding nanostructured aqueous dispersions (red lines) [83]. It is evident from the SAXS patterns in Figure 2 (left) that the internal nanostructures are preserved upon dispersing the bulk phases in excess water, as the same characteristic X-ray diffraction peaks are observed for the dispersed and the non-dispersed phases. 

Small Angle Neutron Scattering (SANS) scatter neutrons from the pores, then the smaller the dimensions of the variations in density distribution, the larger the angle through which the neutrons will be scattered. 

Figure 49 The small angle neutron scattering (SANS) scattering intensity vs. the scattering wave vector q for the silica/silicone oil at particle volume fraction (j)=0.055, under an electric field strength of IkV/mm. Two model curves are presented sticky hard-sphere (SI IS) and fractal model (a = 165 nm, X df = 1.6). Reproduced with permission from C. Gehin, J.

Figure 7.14 Schematic illustration of shearing a block copolymer into single domain texture, and the corresponding SANS scattering pattern.

Since the SANS scattering intensity is generally described as depending, in part, on differences in the interaction energies sap of the hydrogenated and deuterated species, the random partial deuterium substitution leads to an additional interaction randomness that cannot presently be treated with the theory developed here. (The random partial deuteration presumably likewise affects the nuclear reaction analysis data.)... 

Figure 5.10 Experimental SANS scattered intensity of a blend of saturated poly (ethylbutadiene) with high 3,4 content and deuterated polypropylene at three different temperatures. The solid line represents the...

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