Cellulosic liquid crystals for films and fibers

Canejo, J. P.; Monge, Nuno; Echeverria, C.; Fernandes, S. N.; Godinho, M. H.

Publication

Cellulosic liquid crystals for films and fibers

2017Journal article

dc.contributor.author	Canejo, J. P.
dc.contributor.author	Monge, Nuno
dc.contributor.author	Echeverria, C.
dc.contributor.author	Fernandes, S. N.
dc.contributor.author	Godinho, M. H.
dc.date.accessioned	2018-03-01T16:01:08Z
dc.date.available	2018-03-01T16:01:08Z
dc.date.issued	2017
dc.description.abstract	Cellulose, the most abundant natural polymer on earth, is used in numerous applications in our day-to-day life. However, the discovery that cellulose-based systems could lead to the formation of liquid crystalline phases only dates to the 1970s. Compared with all known applications of cellulose, the liquid crystalline behavior has been less considered. Associated with this are the low solubility of cellulose and the existence of a chiral nematic precursor solution and its processing under the action of a shear field, which is used to produce fibers and films. In this review, we first conduct a short review of the main features of cellulosic liquid crystalline phases including the main textures observed by polarizing optical microscopy and the cholesteric phase characteristics of thermotropic and lyotropic systems observed for cellulose and cellulose derivatives. Then, we focus on the rheological properties of liquid crystalline solutions and special attention is given to the formation of striations developed during shear and the formation of the band texture, which appears during the relaxation process. Among the different techniques used, special emphasis is given to the results obtained by coupling rheology with optical microscopy (Rheo-optics) and nuclear magnetic resonance (Rheo-NMR) techniques. Some examples described in the literature, related to the use of cellulose and cellulose derivatives liquid crystals to the production of structural color scaffolds, stimuli-responsive films and fibers, are addressed. In these systems, the initial cholesteric phase determines the unique properties exhibited by the films and the fibers produced from cellulosic liquid crystalline systems.	pt_PT
dc.description.version	info:eu-repo/semantics/publishedVersion	pt_PT
dc.identifier.doi	10.1080/21680396.2017.1394923	pt_PT
dc.identifier.uri	http://hdl.handle.net/10400.21/8181
dc.language.iso	eng	pt_PT
dc.peerreviewed	yes	pt_PT
dc.publisher	Taylor & Francis	pt_PT
dc.relation.publisherversion	https://www.tandfonline.com/doi/full/10.1080/21680396.2017.1394923	pt_PT
dc.rights.uri	http://creativecommons.org/licenses/by-nc/4.0/	pt_PT
dc.subject	Liquid crystals	pt_PT
dc.subject	Cellulose derivatives	pt_PT
dc.subject	Cholesteric liquid crystals	pt_PT
dc.subject	Lyotropic and thermotropic cellulosic systems	pt_PT
dc.subject	Films and fibers	pt_PT
dc.title	Cellulosic liquid crystals for films and fibers	pt_PT
dc.type	journal article
dspace.entity.type	Publication
oaire.citation.endPage	110	pt_PT
oaire.citation.issue	2	pt_PT
oaire.citation.startPage	86	pt_PT
oaire.citation.title	Liquid Crystals Reviews	pt_PT
oaire.citation.volume	5	pt_PT
rcaap.rights	closedAccess	pt_PT
rcaap.type	article	pt_PT