Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites

Detalhes bibliográficos
Autor(a) principal: Santos, Raquel M.
Data de Publicação: 2018
Outros Autores: Mould, Sacha Trevelyan, Formánek, Petr, Paiva, M. C., Covas, J. A.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/1822/60318
Resumo: Carbon nanoparticles tend to form agglomerates with considerable cohesive strength, depending on particle morphology and chemistry, thus presenting different dispersion challenges. The present work studies the dispersion of three types of graphite nanoplates (GnP) with different flake sizes and bulk densities in a polypropylene melt, using a prototype extensional mixer under comparable hydrodynamic stresses. The nanoparticles were also chemically functionalized by covalent bonding polymer molecules to their surface, and the dispersion of the functionalized GnP was studied. The effects of stress relaxation on dispersion were also analyzed. Samples were removed along the mixer length, and characterized by microscopy and dielectric spectroscopy. A lower dispersion rate was observed for GnP with larger surface area and higher bulk density. Significant re-agglomeration was observed for all materials when the deformation rate was reduced. The polypropylene-functionalized GnP, characterized by increased compatibility with the polymer matrix, showed similar dispersion effects, albeit presenting slightly higher dispersion levels. All the composites exhibit dielectric behavior, however, the alternate current (AC) conductivity is systematically higher for the composites with larger flake GnP.
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spelling Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene compositesgraphite nanoplatessurface modificationpolymer compositesdispersionScience & TechnologyCarbon nanoparticles tend to form agglomerates with considerable cohesive strength, depending on particle morphology and chemistry, thus presenting different dispersion challenges. The present work studies the dispersion of three types of graphite nanoplates (GnP) with different flake sizes and bulk densities in a polypropylene melt, using a prototype extensional mixer under comparable hydrodynamic stresses. The nanoparticles were also chemically functionalized by covalent bonding polymer molecules to their surface, and the dispersion of the functionalized GnP was studied. The effects of stress relaxation on dispersion were also analyzed. Samples were removed along the mixer length, and characterized by microscopy and dielectric spectroscopy. A lower dispersion rate was observed for GnP with larger surface area and higher bulk density. Significant re-agglomeration was observed for all materials when the deformation rate was reduced. The polypropylene-functionalized GnP, characterized by increased compatibility with the polymer matrix, showed similar dispersion effects, albeit presenting slightly higher dispersion levels. All the composites exhibit dielectric behavior, however, the alternate current (AC) conductivity is systematically higher for the composites with larger flake GnP.This work was funded by National Funds through FCT-Portuguese Foundation for Science and Technology, Reference UID/CTM/50025/2013 and FEDER funds through the COMPETE 2020 Programme under the project number POCI-01-0145-FEDER-007688. We acknowledge Mrs. Uta Reuter from Leibniz-Institut für Polymerforschung Dresden e.V. for TEM specimen preparation and image acquisition for the composites.info:eu-repo/semantics/publishedVersionMultidisciplinary Digital Publishing InstituteUniversidade do MinhoSantos, Raquel M.Mould, Sacha TrevelyanFormánek, PetrPaiva, M. C.Covas, J. A.2018-02-242018-02-24T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/60318eng2073-436010.3390/polym10020222info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-05-11T05:26:44Zoai:repositorium.sdum.uminho.pt:1822/60318Portal AgregadorONGhttps://www.rcaap.pt/oai/openairemluisa.alvim@gmail.comopendoar:71602024-05-11T05:26:44Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
title Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
spellingShingle Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
Santos, Raquel M.
graphite nanoplates
surface modification
polymer composites
dispersion
Science & Technology
title_short Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
title_full Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
title_fullStr Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
title_full_unstemmed Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
title_sort Effects of particle size and surface chemistry on the dispersion of graphite nanoplates in polypropylene composites
author Santos, Raquel M.
author_facet Santos, Raquel M.
Mould, Sacha Trevelyan
Formánek, Petr
Paiva, M. C.
Covas, J. A.
author_role author
author2 Mould, Sacha Trevelyan
Formánek, Petr
Paiva, M. C.
Covas, J. A.
author2_role author
author
author
author
dc.contributor.none.fl_str_mv Universidade do Minho
dc.contributor.author.fl_str_mv Santos, Raquel M.
Mould, Sacha Trevelyan
Formánek, Petr
Paiva, M. C.
Covas, J. A.
dc.subject.por.fl_str_mv graphite nanoplates
surface modification
polymer composites
dispersion
Science & Technology
topic graphite nanoplates
surface modification
polymer composites
dispersion
Science & Technology
description Carbon nanoparticles tend to form agglomerates with considerable cohesive strength, depending on particle morphology and chemistry, thus presenting different dispersion challenges. The present work studies the dispersion of three types of graphite nanoplates (GnP) with different flake sizes and bulk densities in a polypropylene melt, using a prototype extensional mixer under comparable hydrodynamic stresses. The nanoparticles were also chemically functionalized by covalent bonding polymer molecules to their surface, and the dispersion of the functionalized GnP was studied. The effects of stress relaxation on dispersion were also analyzed. Samples were removed along the mixer length, and characterized by microscopy and dielectric spectroscopy. A lower dispersion rate was observed for GnP with larger surface area and higher bulk density. Significant re-agglomeration was observed for all materials when the deformation rate was reduced. The polypropylene-functionalized GnP, characterized by increased compatibility with the polymer matrix, showed similar dispersion effects, albeit presenting slightly higher dispersion levels. All the composites exhibit dielectric behavior, however, the alternate current (AC) conductivity is systematically higher for the composites with larger flake GnP.
publishDate 2018
dc.date.none.fl_str_mv 2018-02-24
2018-02-24T00:00:00Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/1822/60318
url http://hdl.handle.net/1822/60318
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 2073-4360
10.3390/polym10020222
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Multidisciplinary Digital Publishing Institute
publisher.none.fl_str_mv Multidisciplinary Digital Publishing Institute
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
repository.mail.fl_str_mv mluisa.alvim@gmail.com
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