IUCr journals

Application of in situ vapor sorption small-angle neutron scattering (SANS) to semicrystalline polymers: vapor pathway and structure evolution in semicrystalline linear polyethylene

J. Appl. Cryst. (2005). 38, 734–739

[Semi-crystalline polymers] SANS 2D detector patterns, and circularly averaged profiles, as a function of d14-hexane sorption time. The peak comes from the lamellar structure of the crystalline and amorphous regions in the polyethylene sample. SANS from the dry sample is at the bottom (circle) of the 1D profiles.
Unlike SAXS, SANS has not been successfully applied to study the structure of semicrystalline polyolefins due to the fundamental limitation of negligible neutron contrast between the crystalline and amorphous phases. We demonstrate an in situ vapor sorption SANS technique that circumvents this limitation by diffusing a contrast-generating vapor selectively into the amorphous phase. The enhanced contrast enables the sorption to be followed in real time and structural changes to be correlated with adsorption isotherms. The quality of the data is comparable with synchrotron SAXS data on dry samples.

M.-H. Kim and C. J. Glinka