[en] Copper phthalocyanine (CuPc) blue, commonly named phthalo blue is the most important synthetic organic blue pigment in the 20th and 21st century artists paints. Phthalo blue, which is adopted by artists since 1936, is a polymorphous pigment. Currently, the alpha, beta and epsilon CuPc polymorphs are used in artists paint formulations. The identification of the CuPc crystal form provides technical and chronological information relevant for studying artworks. Raman Spectroscopy (RS) is a very valuable technique for the detection of phthalo blue in paint layers. However, the spectral interpretation is not straightforward concerning the CuPc polymorph distinction. To overcome the problem we have previously developed a procedure combining RS and chemometrical analysis. The experimental results that we obtained have demonstrated its efficiency for predicting the CuPc crystal form in unknown paint samples. In the present work, this procedure was applied on oil-based and acrylic paints from Sam Francis’ studio and the Getty Conservation Institute (GCI) Reference Collection.
Research center :
CEA - Centre Européen en Archéométrie - ULiège
Disciplines :
Arts & humanities: Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences: Multidisciplinary, general & others Chemistry
Author, co-author :
Defeyt, Catherine ; Université de Liège - ULiège > Centre européen en archéométrie
Van Pevenage, Jolien; Universiteit Gent - Ugent
Learner, Tom; Getty Conservation Institute
Vandenabeele, Peter; Universiteit Gent - Ugent
Strivay, David ; Université de Liège - ULiège > Département de physique > Physique nucléaire, atomique et spectroscopie
Language :
English
Title :
Distinction by micro-Raman spectroscopy and chemometrical analysis of copper phthalocyanine blue polymorphs in oil-based and acrylic samples