TIT# An evaluation method for SAXS patterns of fibrillar two-phase systems
     containing oriented particles of moderate anisotropy and short range
     correlation
AUT# Stribeck, N.
SOU# Colloid Polym. Sci. (1989), 267, 301-310
LOC# xv007  @selbst.ftx
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ABS# Starting from the theoretical background of Rulands interface
     distributions, an evaluation method for small-angle x-ray patterns
     arising from oriented fibrillar two-phase structures is proposed. If the
     fibril contains highly oriented particles with only moderate anisotropy
     and if the correlations between those particles within the fibril are
     of short range only, every axial section of the scattering pattern shows
     a one-dimensional Porod law. A procedure of successive model confinement
     using the well known tools of nonlinear regression analysis is described.
     The result of such an analysis for the scattering pattern of an oil
     diluted SBS block copolymer recorded with synchrotron radiation under
     first-cycle stretching is reported. At $\lambda$ = 4 four contributions
     to the scattering pattern could be identified: a) fibrils containing
     well-defined cylinders standing upright; b) fibrils containing lying
     cylinders under destruction; c) stretched-out polybutadiene chains,
     connecting only two polystyrene cylinders and causing the observable
     layer line pattern; and d) stretched-out polybutadiene chains looping
     through the neighboring PS domain and returning to their starting domain.
     In addition, a simple method for determining the height-to-diameter
     ratio of tylinders from the form factor envelope is proposed.