Publication
Aging effects on the rheology of LC solutions of hydroxypropylcellulose
| dc.contributor.author | Leal, Catarina R. | |
| dc.contributor.author | Godinho, M. H. | |
| dc.contributor.author | Martins, A. F. | |
| dc.contributor.author | Fried, F. | |
| dc.date.accessioned | 2024-11-19T15:38:17Z | |
| dc.date.available | 2024-11-19T15:38:17Z | |
| dc.date.issued | 1995-03-01 | |
| dc.description.abstract | We apply the recently developed continuum theory of liquid crystalline polymers1 to interpret the behavior of the shear viscosity η(γ.) and the first normal-stress difference N1(γ.) measured for liquid crystalline solutions (c = 37%, c > c*) of HPC (Aldrich, Mw = 100,000) in acetic acid (AA) with different ages: 1 day, 1 month and 2 years. η(γ.) and N1(γ.) were measured over four decades in γ. N1(γ.) is observed to change from positive to negative and again to positive, as the shear rate γ. increases. η(γ.) shows a small newtonian plateau at low shear rates and a strong shear-thinning at higher values of γ. The rate of decrease of η(γ.) in this region is not monotonous, as usual, but shows an “hesitation” similar to one previously observed in a different system2. The aging effect promotes a “depolymerization”3 of HPC. This, in turn, should have a strong influence on the behavior of Nl(γ.) and η(γ.) which is indeed observed4. All these observations can be rationalized within the framework of the theory1. | pt_PT |
| dc.description.version | info:eu-repo/semantics/publishedVersion | pt_PT |
| dc.identifier.citation | Leal CR, Godinho MH, Martins AF, Fried F – Aging effects on the rheology of LC solutions of hydroxypropylcellulose. Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 261(1), 87-93. https://doi.org/10.1080/10587259508033455 | pt_PT |
| dc.identifier.doi | 10.1080/10587259508033455 | pt_PT |
| dc.identifier.issn | 1058-725X | |
| dc.identifier.uri | http://hdl.handle.net/10400.21/17940 | |
| dc.language.iso | eng | pt_PT |
| dc.peerreviewed | yes | pt_PT |
| dc.publisher | Taylor & Francis | pt_PT |
| dc.subject | liquid crystalline polymers | pt_PT |
| dc.subject | shear viscosity | pt_PT |
| dc.subject | normal-stress difference | pt_PT |
| dc.subject | acetic acid | pt_PT |
| dc.title | Aging effects on the rheology of LC solutions of hydroxypropylcellulose | pt_PT |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.endPage | 93 | pt_PT |
| oaire.citation.issue | 1 | pt_PT |
| oaire.citation.startPage | 87 | pt_PT |
| oaire.citation.title | Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals | pt_PT |
| oaire.citation.volume | 261 | pt_PT |
| person.familyName | Marques Mendes Almeida da Rosa Leal | |
| person.givenName | Catarina | |
| person.identifier | A-2814-2009 | |
| person.identifier.ciencia-id | AF15-486E-BB15 | |
| person.identifier.orcid | 0000-0001-5871-4936 | |
| person.identifier.scopus-author-id | 7005379280 | |
| rcaap.rights | closedAccess | pt_PT |
| rcaap.type | article | pt_PT |
| relation.isAuthorOfPublication | 4db8990d-5eb1-4515-ae7a-68873cf776a5 | |
| relation.isAuthorOfPublication.latestForDiscovery | 4db8990d-5eb1-4515-ae7a-68873cf776a5 |