A closer look at brazilwood and its lake pigments

Detalhes bibliográficos
Autor(a) principal: Vitorino, Tatiana Mendes
Data de Publicação: 2012
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10362/10179
Resumo: Dissertação para obtenção do Grau de Mestre em Mestrado em Conservação e Restauro, especialização em Ciências da Conservação
id RCAP_9e7d5fe160a357e3d23f80f5cdcb524c
oai_identifier_str oai:run.unl.pt:10362/10179
network_acronym_str RCAP
network_name_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository_id_str 7160
spelling A closer look at brazilwood and its lake pigmentsBook of hourBrazileinBrazilwoodLake pigment characterisationLivro de como se fazem as coresWinsor & NewtonDissertação para obtenção do Grau de Mestre em Mestrado em Conservação e Restauro, especialização em Ciências da ConservaçãoBrazilwood is a soluble redwood that was used as source of organic dye and for lake pigments. It was widely applied in medieval times to colour textiles and in the form of pigment for manuscript illumination and, although it is relatively unstable, it is still found in the 19th oil palette. However, this colorant has received little attention. In this sense, the present work aims to contribute knowledge on the characterisation of brazilwood and its lake pigments. The flavonoid brazilein is the red chromophore that can be extracted from the brazilwood tree. To study with more detail its behaviour, the molecule was isolated from brazilwood scrapes. As confirmed by NMR and HPLC-DAD, a high purity compound was obtained (for which a pKa1 of 7 was determined) and a pure brazilein-Al3+ complex was produced. Characterisation with UV-Vis spectroscopy and μ-spectrofluorimetry revealed that in its acidic form, the chromophore presents absorption, excitation and emission maxima at 446, 475 and 536 nm, respectively, and at 540, 548 and 560 nm when deprotonated. When complexed with Al3+ these values are changed to 510, 520 and 585 nm. Brazilwood lake reconstructions with as much historical accuracy as possible were also prepared based on recipes from the 15th century documentary text Livro de como se fazem as cores and the Winsor & Newton 19th century archive. This led to a greater understanding of the manufacture of the lakes and its evolution through time. Furthermore, in order to investigate the best strategy to characterise such pigments and paints, and to provide reference samples, the lakes produced and applied as temperas were then analysed by colorimetry, FTIR, SEM-EDS, FORS and UV-Vis μ-spectrofluorimetry. Despite some differences exist between the two sources, mainly with respect to the dye extraction method, both are guided by the same principles and are constructed in order that the same final pH, adequate for pigment precipitation, is obtained. In particular, the 15th century Livro de como se fazem as cores, so distant in time, allowed for the successful preparation of brazilwood lake pigments, which can be obtained in a variety of different hues from light pink to dark red and purple. Concerning the analysis carried out, FTIR was essential to characterise extenders, while FORS spectra (λabs 560 nm) and μ-spectrofluorimetry (λex 553 nm for excitation and λem 585-90 nm for emission) data were very consistent and fundamental to identify the brazilwood chromophore. These three techniques were essential and complementary in the characterisation of the paints produced. Medieval reconstructions were compared with pink and red colours of illuminations found in three French books of hours (Palácio Nacional de Mafra, Portugal) from the 15th century. Good correlation between FTIR, FORS and μ-spectrofluorimetry spectra of the reconstructions and historic samples suggest that the illuminations colours were prepared with brazilwood lakes.Faculdade de Ciências e TecnologiaMelo, Maria JoãoOtero, VanessaCarlyle, LeslieRUNVitorino, Tatiana Mendes2013-07-25T09:41:04Z20122012-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/10179enginfo: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:RCAAP2024-03-11T03:43:45Zoai:run.unl.pt:10362/10179Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:19:17.728197Repositório 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 A closer look at brazilwood and its lake pigments
title A closer look at brazilwood and its lake pigments
spellingShingle A closer look at brazilwood and its lake pigments
Vitorino, Tatiana Mendes
Book of hour
Brazilein
Brazilwood
Lake pigment characterisation
Livro de como se fazem as cores
Winsor & Newton
title_short A closer look at brazilwood and its lake pigments
title_full A closer look at brazilwood and its lake pigments
title_fullStr A closer look at brazilwood and its lake pigments
title_full_unstemmed A closer look at brazilwood and its lake pigments
title_sort A closer look at brazilwood and its lake pigments
author Vitorino, Tatiana Mendes
author_facet Vitorino, Tatiana Mendes
author_role author
dc.contributor.none.fl_str_mv Melo, Maria João
Otero, Vanessa
Carlyle, Leslie
RUN
dc.contributor.author.fl_str_mv Vitorino, Tatiana Mendes
dc.subject.por.fl_str_mv Book of hour
Brazilein
Brazilwood
Lake pigment characterisation
Livro de como se fazem as cores
Winsor & Newton
topic Book of hour
Brazilein
Brazilwood
Lake pigment characterisation
Livro de como se fazem as cores
Winsor & Newton
description Dissertação para obtenção do Grau de Mestre em Mestrado em Conservação e Restauro, especialização em Ciências da Conservação
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-01-01T00:00:00Z
2013-07-25T09:41:04Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10362/10179
url http://hdl.handle.net/10362/10179
dc.language.iso.fl_str_mv eng
language eng
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 Faculdade de Ciências e Tecnologia
publisher.none.fl_str_mv Faculdade de Ciências e Tecnologia
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
_version_ 1799137836810633216

Registros relacionados