- Tytuł:
- Dynamics of ¹H-¹³C Cross Polarization in Nuclear Magnetic Resonance of Poly(3-hydroxybutyrate)
- Autorzy:
-
Koval'aková, M.
Fričová, O.
Hutníková, M.
Hronský, V.
Olčák, D. - Powiązania:
- https://bibliotekanauki.pl/articles/1032838.pdf
- Data publikacji:
- 2017-04
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
74.25.nj
79.60.Fr
61.05.Qr - Opis:
- Poly(3-hydroxybutyrate) (PHB) is a semicrystalline biodegradable polymer with chains consisting of methyl (CH₃), methylene (CH₂), methine (CH) and carbonyl (CO) groups. The ¹H-¹³C cross polarization NMR measurements were performed on an as-supplied powder PHB sample at a magic-angle spinning rate of 10 kHz. The measured cross polarization build-up curves and their analysis provided information on the dynamics of ¹H-¹³C NMR cross polarization in functional groups with directly bonded hydrogens. The measurements required setting up the Hartmann-Hahn condition, which was inferred from the Hartmann-Hahn matching profiles measured for each functional group. The cross polarization build-up curves displayed an oscillatory course, which indicates the presence of rigid ¹H-¹³C spin pairs isolated from the lattice. The frequency of the observed oscillations is directly proportional to the ¹H-¹³C dipolar coupling constant, which is related to the C-H distance and its value also reflects the mobility of particular functional groups. The values of dipolar coupling constants were derived from splittings in the Fourier transforms of cross polarization build-up curves. The mobility of particular groups was assessed with the order parameter ⟨S⟩ calculated using experimental and rigid lattice values of dipolar coupling constants.
- Źródło:
-
Acta Physica Polonica A; 2017, 131, 4; 1162-1164
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł