ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The first “linear” range of inverse reduced scattering intensity of N stems in monodisperse clusters versus q2 with the initial slope Rcc2/2 is followed by a second nearly 20% steeper and 10 times wider quasi-linear range. The difference slightly decreases with polydispersity of the clusters. This case will not be discussed here. One may deduce from the second range the fictive number N of stems and gyration radius Rcc which differ less than 10% from the true values obtained from the first “linear” range. But the fine structure of the equal monoplanar clusters on the scattering molecule may change enormously with interior gaps while keeping constant the scattering intensity in the interesting region, N and Rcc of the cluster. In the sensitive range of the first two quasi-linear ranges all these 3 quantities are so little affected by the changes of fine structure that small angle neutron scattering (SANS) yielding N and Rcc does not permit any statement on these changes. The calculations of SANS results with some equidistant gaps which retain N and Rcc yield the same intensity distribution in the interesting range. This follows from the fact that N commands the intensity while Rcc rules not only the first but also the second quasi-linear range. The perfect merging of the first with the second quasi-linear ranges in the SANS of polyethylene demands a special arrangement of a single gap separating one single stem from the bulk of the active stems in the cluster.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1989.021900714
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