Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites

Detalhes bibliográficos
Autor(a) principal: Petrolini, Davi D. [UNESP]
Data de Publicação: 2017
Outros Autores: Urquieta-González, Ernesto A., Pulcinelli, Sandra H. [UNESP], Santilli, Celso V. [UNESP], Martins, Leandro [UNESP]
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://dx.doi.org/10.1016/j.micromeso.2016.11.011
http://hdl.handle.net/11449/178435
Resumo: A new sol-gel method mediated by the use of paraffin emulsions is presented for the synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites. Prior to the synthesis, the construction of ternary diagrams for paraffin/surfactant/ethanol helped to identify the most suitable compositional synthesis domain. Two distinct regions, denoted L1 (transparent microemulsion) and L2 (opaque emulsion) were identified for low and high concentrations of paraffins, respectively. The ternary diagrams revealed some features: i) n-hexane (C6) had the smallest L2 region; ii) the high viscosity of n-octadecane (C18) did not allow control of phase separation, and iii) the most suitable paraffin for the use as the emulsifier was the intermediate-sized n-dodecane (C12). The use of paraffin in concentrations included in the L1 region did not contribute to the creation of pores, but the emulsion templating in the L2 region led to hierarchical porous hydrotalcites when were calcined up to 250 °C having enhanced textural properties and presenting mesopores and macropores with mean sizes of 0.02 and 1 μm, respectively. The slit-like shaped mesopores were caused by the partial exfoliation of hydrotalcite layers unordered packed around the emulsion droplets, while the macropores arose from voids left by the droplets after thermal treatment. The singular textural properties of the studied Al-Mg hierarchical porous hydrotalcites turns the emulsion mediated-synthesis a potential method to obtain more efficient catalysts to be used in process involving bulky molecules.
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spelling Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcitesHierarchical porous structureHydrotalcitesParaffin-surfactant emulsionSol-gel synthesisA new sol-gel method mediated by the use of paraffin emulsions is presented for the synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites. Prior to the synthesis, the construction of ternary diagrams for paraffin/surfactant/ethanol helped to identify the most suitable compositional synthesis domain. Two distinct regions, denoted L1 (transparent microemulsion) and L2 (opaque emulsion) were identified for low and high concentrations of paraffins, respectively. The ternary diagrams revealed some features: i) n-hexane (C6) had the smallest L2 region; ii) the high viscosity of n-octadecane (C18) did not allow control of phase separation, and iii) the most suitable paraffin for the use as the emulsifier was the intermediate-sized n-dodecane (C12). The use of paraffin in concentrations included in the L1 region did not contribute to the creation of pores, but the emulsion templating in the L2 region led to hierarchical porous hydrotalcites when were calcined up to 250 °C having enhanced textural properties and presenting mesopores and macropores with mean sizes of 0.02 and 1 μm, respectively. The slit-like shaped mesopores were caused by the partial exfoliation of hydrotalcite layers unordered packed around the emulsion droplets, while the macropores arose from voids left by the droplets after thermal treatment. The singular textural properties of the studied Al-Mg hierarchical porous hydrotalcites turns the emulsion mediated-synthesis a potential method to obtain more efficient catalysts to be used in process involving bulky molecules.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Instituto de Química UNESP - Univ. Estadual Paulista, Rua Prof. Francisco Degni 55Centro de Pesquisas em Materiais Avançados e Energia - Univ. Federal de São Carlos, Rodovia Washington Luis, km 235Instituto de Química UNESP - Univ. Estadual Paulista, Rua Prof. Francisco Degni 55FAPESP: 2013/01328-0FAPESP: 2015/05321-5Universidade Estadual Paulista (Unesp)Universidade Federal de São Carlos (UFSCar)Petrolini, Davi D. [UNESP]Urquieta-González, Ernesto A.Pulcinelli, Sandra H. [UNESP]Santilli, Celso V. [UNESP]Martins, Leandro [UNESP]2018-12-11T17:30:16Z2018-12-11T17:30:16Z2017-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article149-158application/pdfhttp://dx.doi.org/10.1016/j.micromeso.2016.11.011Microporous and Mesoporous Materials, v. 240, p. 149-158.1387-1811http://hdl.handle.net/11449/17843510.1016/j.micromeso.2016.11.0112-s2.0-849972858872-s2.0-84997285887.pdf55842986818708650000-0002-8356-8093Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengMicroporous and Mesoporous Materials1,080info:eu-repo/semantics/openAccess2023-11-24T06:12:02Zoai:repositorio.unesp.br:11449/178435Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T18:34:13.710228Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
title Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
spellingShingle Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
Petrolini, Davi D. [UNESP]
Hierarchical porous structure
Hydrotalcites
Paraffin-surfactant emulsion
Sol-gel synthesis
title_short Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
title_full Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
title_fullStr Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
title_full_unstemmed Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
title_sort Emulsion-mediated synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites
author Petrolini, Davi D. [UNESP]
author_facet Petrolini, Davi D. [UNESP]
Urquieta-González, Ernesto A.
Pulcinelli, Sandra H. [UNESP]
Santilli, Celso V. [UNESP]
Martins, Leandro [UNESP]
author_role author
author2 Urquieta-González, Ernesto A.
Pulcinelli, Sandra H. [UNESP]
Santilli, Celso V. [UNESP]
Martins, Leandro [UNESP]
author2_role author
author
author
author
dc.contributor.none.fl_str_mv Universidade Estadual Paulista (Unesp)
Universidade Federal de São Carlos (UFSCar)
dc.contributor.author.fl_str_mv Petrolini, Davi D. [UNESP]
Urquieta-González, Ernesto A.
Pulcinelli, Sandra H. [UNESP]
Santilli, Celso V. [UNESP]
Martins, Leandro [UNESP]
dc.subject.por.fl_str_mv Hierarchical porous structure
Hydrotalcites
Paraffin-surfactant emulsion
Sol-gel synthesis
topic Hierarchical porous structure
Hydrotalcites
Paraffin-surfactant emulsion
Sol-gel synthesis
description A new sol-gel method mediated by the use of paraffin emulsions is presented for the synthesis of hierarchical mesoporous-macroporous Al-Mg hydrotalcites. Prior to the synthesis, the construction of ternary diagrams for paraffin/surfactant/ethanol helped to identify the most suitable compositional synthesis domain. Two distinct regions, denoted L1 (transparent microemulsion) and L2 (opaque emulsion) were identified for low and high concentrations of paraffins, respectively. The ternary diagrams revealed some features: i) n-hexane (C6) had the smallest L2 region; ii) the high viscosity of n-octadecane (C18) did not allow control of phase separation, and iii) the most suitable paraffin for the use as the emulsifier was the intermediate-sized n-dodecane (C12). The use of paraffin in concentrations included in the L1 region did not contribute to the creation of pores, but the emulsion templating in the L2 region led to hierarchical porous hydrotalcites when were calcined up to 250 °C having enhanced textural properties and presenting mesopores and macropores with mean sizes of 0.02 and 1 μm, respectively. The slit-like shaped mesopores were caused by the partial exfoliation of hydrotalcite layers unordered packed around the emulsion droplets, while the macropores arose from voids left by the droplets after thermal treatment. The singular textural properties of the studied Al-Mg hierarchical porous hydrotalcites turns the emulsion mediated-synthesis a potential method to obtain more efficient catalysts to be used in process involving bulky molecules.
publishDate 2017
dc.date.none.fl_str_mv 2017-03-01
2018-12-11T17:30:16Z
2018-12-11T17:30:16Z
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://dx.doi.org/10.1016/j.micromeso.2016.11.011
Microporous and Mesoporous Materials, v. 240, p. 149-158.
1387-1811
http://hdl.handle.net/11449/178435
10.1016/j.micromeso.2016.11.011
2-s2.0-84997285887
2-s2.0-84997285887.pdf
5584298681870865
0000-0002-8356-8093
url http://dx.doi.org/10.1016/j.micromeso.2016.11.011
http://hdl.handle.net/11449/178435
identifier_str_mv Microporous and Mesoporous Materials, v. 240, p. 149-158.
1387-1811
10.1016/j.micromeso.2016.11.011
2-s2.0-84997285887
2-s2.0-84997285887.pdf
5584298681870865
0000-0002-8356-8093
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Microporous and Mesoporous Materials
1,080
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 149-158
application/pdf
dc.source.none.fl_str_mv Scopus
reponame:Repositório Institucional da UNESP
instname:Universidade Estadual Paulista (UNESP)
instacron:UNESP
instname_str Universidade Estadual Paulista (UNESP)
instacron_str UNESP
institution UNESP
reponame_str Repositório Institucional da UNESP
collection Repositório Institucional da UNESP
repository.name.fl_str_mv Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)
repository.mail.fl_str_mv
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