TY - JOUR
T1 - Effect of cellulose nanocrystals in a cellulosic liquid crystal behaviour under low shear (regime I): Structure and molecular dynamics
AU - Echeverria, Coro
AU - Fernandes, Susete Nogueira
AU - Almeida, Pedro L
AU - Godinho, Maria H
N1 - Sem PDF conforme despacho.
info:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBPD%2F88779%2F2012/PT#
info:eu-repo/grantAgreement/FCT/5876/147333/PT#
C. Echeverria and S.N. Fernandes acknowledge the Minister of Science, Technology and Higher Education for National Funds, European Social Funds and FCT for fellowship number SFRH/BPD/88779/2012 and SFRH/BDP/78430/2011, respectively. We acknowledge LabRMN-CENIMAT at FCT-UNL and RNRMN for access to the facilities. RNRMN is supported with funds from the Foundation for Science and Technology. This work is also funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under projects POCI-01-0145-FEDER-007688 (Reference UID/CTM/50025), PTDC/FIS-NAN/0117/2014 and PTDC/CTM-BIO/6178/2014.
PY - 2016/11
Y1 - 2016/11
N2 - In the field of cellulosic liquid crystals, attempts to establish the relationship between structure/properties have been developed. Above a critical concentration in an aqueous solution, hydroxypropylcellulose self-assembles in order to form cholesteric liquid crystal phases (LC-HPC). In this work we aim to understand how the incorporation of a low content of cellulose nanocrystals (CNC) within LC-HPC/H2O (50 wt%), could influence the behaviour of the system when subjected to low shear rates, where the cholesteric phase still persists. The analysis of the deuterium spectrum and the T-2 (transversal relaxation) values confirm that the mobility of LC-HPC at low shear rates is restricted due to CNC, and consequently so is the flow of the cholesteric polydomains. These effects are more evident in the some sample containing 2 wt% of CNC; besides needing more strain units to induce some degree of order, the achieved degree of order is recovered faster when compared to the reference sample.
AB - In the field of cellulosic liquid crystals, attempts to establish the relationship between structure/properties have been developed. Above a critical concentration in an aqueous solution, hydroxypropylcellulose self-assembles in order to form cholesteric liquid crystal phases (LC-HPC). In this work we aim to understand how the incorporation of a low content of cellulose nanocrystals (CNC) within LC-HPC/H2O (50 wt%), could influence the behaviour of the system when subjected to low shear rates, where the cholesteric phase still persists. The analysis of the deuterium spectrum and the T-2 (transversal relaxation) values confirm that the mobility of LC-HPC at low shear rates is restricted due to CNC, and consequently so is the flow of the cholesteric polydomains. These effects are more evident in the some sample containing 2 wt% of CNC; besides needing more strain units to induce some degree of order, the achieved degree of order is recovered faster when compared to the reference sample.
KW - Cellulose nanocrystals
KW - Liquid crystalline solution
KW - Hydroxypropylcellulose
KW - Rheology
KW - Rheo-NMR
U2 - 10.1016/j.eurpolymj.2016.10.009
DO - 10.1016/j.eurpolymj.2016.10.009
M3 - Article
SN - 0014-3057
VL - 84
SP - 675
EP - 684
JO - European Polymer Journal
JF - European Polymer Journal
ER -