TIT# Small-Angle X-ray Scattering Functions in the Vicinity of Zero
     Scattering Angle with an Application to Polymer Blends
AUT# Stribeck, N.
SOU# Macromolecules (1996), 29(22), 7217-7220
LOC# xv024  @selbst.ftx
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ABS# The small-angle X-ray
     scattering of isotropic scatterers is studied in the region near
     zero scattering angles, where void scattering may contribute to the
     scattering power Q.  Since Q is evaluated by an integration, the
     corresponding integrands I1(s) (for point collimation) and ~I1(s)
     (for slit focus) as well as the relations between them are studied.
     The properties of both their moments and their Taylor series
     expansions are discussed.  For a lamellar 2-phase system, which is
     frequently observed in semicrystalline or microphase-separated polymers
     , analysis equations are presented.  They can help (1) to extrapolate
     I1(s) and ~I1(s) toward zero scattering angle, (2) to detect void
     scattering, and (3) to improve the modeling of the paracrystalline stack
     even in the case of considerable roughness of the layer surfaces.
     An example for a set of semicrystalline HDPE samples illustrates how to
     quantify void scattering and the effects of interfacial statistical
     structure.