Deuteron NMR resolved mesogen vs. crosslinker molecular order and reorientational exchange in liquid single crystal elastomers

0463036 - FZÚ 2017 RIV GB eng J - Článek v odborném periodiku
Milavec, J. - Domenici, V. - Zupančič, B. - Rešetič, A. - Bubnov, Alexej - Zalar, B.
Deuteron NMR resolved mesogen vs. crosslinker molecular order and reorientational exchange in liquid single crystal elastomers.
Physical Chemistry Chemical Physics. Roč. 18, č. 5 (2016), s. 4071-4077. ISSN 1463-9076. E-ISSN 1463-9084
Grant CEP: GA ČR GA15-02843S; GA MŠMT(CZ) LD14007
Grant ostatní: EU - ICT(XE) COST Action IC1208
Institucionální podpora: RVO:68378271
Klíčová slova: liquid single crystal elastomer * NMR * liquid crystal * molecular order * monomers
Kód oboru RIV: JJ - Ostatní materiály
Impakt faktor: 4.123, rok: 2016

Differences in the temperature behaviour of orientational ordering of structurally equivalent side-chain liquid single crystal elastomers (LSCEs), 2 H-labelled in the crosslinker and mesogen, have been studied by deuteron quadrupole-perturbed NMR. The impact of nematic director reorientations on the deuteron NMR spectral shapes was analyzed in terms of discrete reorientational exchange model. This provided for the determination of the degree of nematic director alignment and for the quantification of the influence of the reorientational exchange on the 2H NMR spectra in terms of two parameters, the nematic director orientational dispersion parameter and the motional effectiveness parameter. Comparative analysis of model simulations and experimental spectra reveals that mesogenic molecules in LSCEs exhibit faster reorientational dynamics as compared to crosslinker molecules and that mesogens and crosslinkers exhibit similar and rather substantial static director orientational disorder.


Trvalý link: http://hdl.handle.net/11104/0262468