Dynamic investigations of liquid crystalline elastomers and their constituents by .sup.2./sup.H NMR spectroscopy

0499774 - FZÚ 2019 RIV GB eng J - Journal Article
Milavec, J. - Rešetič, A. - Bubnov, Alexej - Zalar, B. - Domenici, V.
Dynamic investigations of liquid crystalline elastomers and their constituents by ²H NMR spectroscopy.
Liquid Crystals. Roč. 45, 13-15 (2018), s. 2158-2173. ISSN 0267-8292. E-ISSN 1366-5855
R&D Projects: GA ČR GA16-12150S
Grant - others:EU - ICT(XE) COST Action IC1208
Institutional support: RVO:68378271
Keywords : liquid crystalline elastomer * NMR * mesogen * crosslinker * dynamic * liquid crystals * artificial muscles * soft actuators
OECD category: Materials engineering
Impact factor: 3.078, year: 2018

Several side-chain liquid single crystalline elastomers (LSCEs) were investigated by means of 2H NMR spectroscopy focusing on the temperature dependence of the spectral line width and spectral shape, as well as the T-dependence of spin-lattice and spin-spin relaxation times (T1 and T2). All measurements were performed at the Larmor frequency of 76.753 MHz for 2H. The LSCEs were prepared in the form of monodomain films by using either 2H-labelled monomers (or co-monomers), 2H-labelled crosslinkers or 2H-labelled molecular probes free to diffuse in the LSCE matrix. The main features of the measured 2H NMR properties (static and dynamic ones) in these different cases were discussed and compared with those of low-molecular-weight mesogens in the nematic and SmA phases. Among all investigated LSCEs, those 2H-labelled on the crosslinker sites present distinct properties either on the 2H NMR spectral line width and spectral shape in the paranematic and in the nematic phases.
Permanent Link: http://hdl.handle.net/11104/0292827