Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix

Autores
Hoppe, Cristina Elena; Galante, Maria Jose; Oyanguren, Patricia Angelica; Williams, Roberto Juan Jose
Año de publicación
2004
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Thermally reversible light scattering (TRLS) films were synthesized by the reaction-induced phase separation of solutions of N-4-ethoxybenzylidene- 4′-n-butylaniline (EBBA; 20-50 wt %) and polystyrene (PS; 1-5 wt %) in diglycidyl ether of bisphenol A (DGEBA), using benzyldimethylamine (BDMA) (0.06 mol with respect to epoxy groups), to initiate the polymerization. The material obtained after complete reaction consisted of a dispersion of EBBA/PS droplets in the epoxy network partially swollen by EBBA. The fractionation of EBBA between both phases was estimated using a simple thermodynamic model. Due to the matching of refractive indices of the three components, the multiphasic material was transparent above the nematic-isotropic transition temperature (TNI) of the EBBA/PS droplets. Below TNI the material exhibited a sharp transition to an opaque state due to the mismatching of refractive indices when EBBA was segregated as a nematic phase inside the droplets. The PS addition produced a significant decrease of the cloud-point conversion with respect to formulations devoid of PS. This led to relatively large domains that behave efficiently as light scattering centers in the PS-modified material, enabling high contrast ratios between transparent and opaque states to be obtained. The morphologies generated, and the corresponding optical properties of the TRLS films, did not change in the course of successive cooling/heating cycles.
Fil: Hoppe, Cristina Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
Fil: Galante, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
Fil: Oyanguren, Patricia Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
Fil: Williams, Roberto Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
Materia
PDLC
Polystyrene
Epoxy
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/98937
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/98937
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrixHoppe, Cristina ElenaGalante, Maria JoseOyanguren, Patricia AngelicaWilliams, Roberto Juan JosePDLCPolystyreneEpoxyhttps://purl.org/becyt/ford/2.5https://purl.org/becyt/ford/2Thermally reversible light scattering (TRLS) films were synthesized by the reaction-induced phase separation of solutions of N-4-ethoxybenzylidene- 4′-n-butylaniline (EBBA; 20-50 wt %) and polystyrene (PS; 1-5 wt %) in diglycidyl ether of bisphenol A (DGEBA), using benzyldimethylamine (BDMA) (0.06 mol with respect to epoxy groups), to initiate the polymerization. The material obtained after complete reaction consisted of a dispersion of EBBA/PS droplets in the epoxy network partially swollen by EBBA. The fractionation of EBBA between both phases was estimated using a simple thermodynamic model. Due to the matching of refractive indices of the three components, the multiphasic material was transparent above the nematic-isotropic transition temperature (TNI) of the EBBA/PS droplets. Below TNI the material exhibited a sharp transition to an opaque state due to the mismatching of refractive indices when EBBA was segregated as a nematic phase inside the droplets. The PS addition produced a significant decrease of the cloud-point conversion with respect to formulations devoid of PS. This led to relatively large domains that behave efficiently as light scattering centers in the PS-modified material, enabling high contrast ratios between transparent and opaque states to be obtained. The morphologies generated, and the corresponding optical properties of the TRLS films, did not change in the course of successive cooling/heating cycles.Fil: Hoppe, Cristina Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Galante, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Oyanguren, Patricia Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Williams, Roberto Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaAmerican Chemical Society2004-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/98937Hoppe, Cristina Elena; Galante, Maria Jose; Oyanguren, Patricia Angelica; Williams, Roberto Juan Jose; Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix; American Chemical Society; Macromolecules; 37; 14; 7-2004; 5352-53570024-9297CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1021/ma0496955info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/ma0496955info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T15:02:45Zoai:ri.conicet.gov.ar:11336/98937instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 15:02:45.793CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
title Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
spellingShingle Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
Hoppe, Cristina Elena
PDLC
Polystyrene
Epoxy
title_short Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
title_full Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
title_fullStr Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
title_full_unstemmed Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
title_sort Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix
dc.creator.none.fl_str_mv Hoppe, Cristina Elena
Galante, Maria Jose
Oyanguren, Patricia Angelica
Williams, Roberto Juan Jose
author Hoppe, Cristina Elena
author_facet Hoppe, Cristina Elena
Galante, Maria Jose
Oyanguren, Patricia Angelica
Williams, Roberto Juan Jose
author_role author
author2 Galante, Maria Jose
Oyanguren, Patricia Angelica
Williams, Roberto Juan Jose
author2_role author
author
author
dc.subject.none.fl_str_mv PDLC
Polystyrene
Epoxy
topic PDLC
Polystyrene
Epoxy
purl_subject.fl_str_mv https://purl.org/becyt/ford/2.5
https://purl.org/becyt/ford/2
dc.description.none.fl_txt_mv Thermally reversible light scattering (TRLS) films were synthesized by the reaction-induced phase separation of solutions of N-4-ethoxybenzylidene- 4′-n-butylaniline (EBBA; 20-50 wt %) and polystyrene (PS; 1-5 wt %) in diglycidyl ether of bisphenol A (DGEBA), using benzyldimethylamine (BDMA) (0.06 mol with respect to epoxy groups), to initiate the polymerization. The material obtained after complete reaction consisted of a dispersion of EBBA/PS droplets in the epoxy network partially swollen by EBBA. The fractionation of EBBA between both phases was estimated using a simple thermodynamic model. Due to the matching of refractive indices of the three components, the multiphasic material was transparent above the nematic-isotropic transition temperature (TNI) of the EBBA/PS droplets. Below TNI the material exhibited a sharp transition to an opaque state due to the mismatching of refractive indices when EBBA was segregated as a nematic phase inside the droplets. The PS addition produced a significant decrease of the cloud-point conversion with respect to formulations devoid of PS. This led to relatively large domains that behave efficiently as light scattering centers in the PS-modified material, enabling high contrast ratios between transparent and opaque states to be obtained. The morphologies generated, and the corresponding optical properties of the TRLS films, did not change in the course of successive cooling/heating cycles.
Fil: Hoppe, Cristina Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
Fil: Galante, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
Fil: Oyanguren, Patricia Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
Fil: Williams, Roberto Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina
description Thermally reversible light scattering (TRLS) films were synthesized by the reaction-induced phase separation of solutions of N-4-ethoxybenzylidene- 4′-n-butylaniline (EBBA; 20-50 wt %) and polystyrene (PS; 1-5 wt %) in diglycidyl ether of bisphenol A (DGEBA), using benzyldimethylamine (BDMA) (0.06 mol with respect to epoxy groups), to initiate the polymerization. The material obtained after complete reaction consisted of a dispersion of EBBA/PS droplets in the epoxy network partially swollen by EBBA. The fractionation of EBBA between both phases was estimated using a simple thermodynamic model. Due to the matching of refractive indices of the three components, the multiphasic material was transparent above the nematic-isotropic transition temperature (TNI) of the EBBA/PS droplets. Below TNI the material exhibited a sharp transition to an opaque state due to the mismatching of refractive indices when EBBA was segregated as a nematic phase inside the droplets. The PS addition produced a significant decrease of the cloud-point conversion with respect to formulations devoid of PS. This led to relatively large domains that behave efficiently as light scattering centers in the PS-modified material, enabling high contrast ratios between transparent and opaque states to be obtained. The morphologies generated, and the corresponding optical properties of the TRLS films, did not change in the course of successive cooling/heating cycles.
publishDate 2004
dc.date.none.fl_str_mv 2004-07
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/98937
Hoppe, Cristina Elena; Galante, Maria Jose; Oyanguren, Patricia Angelica; Williams, Roberto Juan Jose; Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix; American Chemical Society; Macromolecules; 37; 14; 7-2004; 5352-5357
0024-9297
CONICET Digital
CONICET
url http://hdl.handle.net/11336/98937
identifier_str_mv Hoppe, Cristina Elena; Galante, Maria Jose; Oyanguren, Patricia Angelica; Williams, Roberto Juan Jose; Thermally reversible light scattering films based on droplets of a liquid crystal (N-4-ethoxybenzylidene-4′-n-butylaniline)/polystyrene solution dispersed in an epoxy matrix; American Chemical Society; Macromolecules; 37; 14; 7-2004; 5352-5357
0024-9297
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1021/ma0496955
info:eu-repo/semantics/altIdentifier/url/https://pubs.acs.org/doi/10.1021/ma0496955
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.22299

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