Intensity profile, SANS

Scattering methods such as SANS, SAXS, as well as DLS and SLS have been applied to temperature-sensitive microgels in several studies. " However, scattering intensity profiles are often investigated in the high-q regime only. In this case, the applied model equations are those of the limiting behavior and do not describe the stmcture of the entire particle. 

Figure 7. a.) SANS profile of a PS/PVME blend as a function of temperature at ambient pressure. The divergence of scattered intensity at low Q reveals an LCST of 155 °C b.) SANS profile of a PS/PVME blend as a function of density at 40 C. Again, the divergence of scattered intensity at low Q reveals transition from the phase-mixed to the phase separated state. 

As described below, the HAS-derived nitroxides in heterophasic polymer systems perform a triple role. First, they provide the contrast needed in the imaging experiments. Second, they enable the visualization of polymer morphology, based on the detection of two dynamically different components detected in the ESR spectra of the nitroxides in ABS, for example, the two sites, fast (F) and slow (S), have been assigned to location of nitroxides in butadiene-rich and styrene-acrylonitrile (SAN)-rich domains, respectively. Third, the spatial variation of the ESR spectra of nitroxides (in terms of intensity and line shapes) with treatment time, t, provides detailed information on the extent of degradation in the different miCTodomains. These experiments made possible the determination of the concentration profiles of the nitroxides from ID ESRl, and also of the spectral profiles from 2D spectral-spatial ESRI, both in a nondestructive way. In these studies the nitroxides, which are the contrast agents, are part of the systan therefore these studies represent the evolution of ESRl techniques beyond phantoms. 

On contrast with Wa, SANS curve is intense in the small q-range, so that the profile gives evidence for a large contrihution of mesopores. These quahtative observations are in agreement with pore volume distributions obtained by CO2 and CeHe adsorptiometry since the specific pores volume in mesopores for Wa is 4 times higher than those of CSa sample. 

SANS and LS experiments, In general, SANS intensity distribution function can be decomposed into an intra-particle structure factor and an inter-particle structure factor. An explicit polymer segment distribution profile, called a Cap-and-Gown model, has been proposed for the calculation of the intra-particle structure factor and an analytical expression fcv the inter-particle structure ctc - based on an adhesive hru-d spho% model is given,... 

Fig. 49 SANS profiles from C24 solutions in d-decme at -20 °C for 0.5% (open circles) and 1% (open triangles) wax contents. The solid lines depict the power law behavior of the scattered intensity, while the dotted line represents the single wax molecule form factor in d-decane for a 0.5% wax volume fraction...

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