Naslov
Effect of diamagnetic susceptibility in NMR measurements in diblock copolymers

Autori
Sotta, Paul ; Valić, Srećko ; Deloche, Bertrand ; Maring, D. ; Spiess, Heinz Wolfgang

Izvornik
Acta Polymerica (0323-7648) 50 (1999), 5-6; 205-213

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
angle-spinning nmr; magic-angle; lamellar structure; orientation; order

Sažetak
Symmetric diblock copolymers in the lamellar phase are studied by NMR. H-2 NMR spectra obtained in macroscopically oriented monodomains show an absolute frequency shift of a few ppm, which depends of the orientation of the sample with respect to the magnetic field. This is interpreted as due to the anisotropy of the diamagnetic susceptibility, related to the lamellar structure itself rather than to an orientational order of polymer chain segments. The spectra obtained in both 2D C-13 and H-1 rotor-synchronized MAS experiments reflect the same effect. Specifically, we show that H-1 rotor-synchronized MAS experiments allow us to discriminate unambiguously the effect of diamagnetic susceptibility anisotropy and the effect of molecular orientation.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA