Discipline: Technology and Engineering
Subcategory: Materials Science
Maritza Sanchez - California State University, Los Angeles
Co-Author(s): Benjamin Myers and Vinayak Dravid, Northwestern University Celine Daher, Inge Fiedler, and Francesca Casadio, Art Institute of Chicago
Cobalt based blue pigments were commonly used in paintings of 19th century artists like Pierre-Auguste Renoir and Gustave Caillebotte. Recently, there were traces of magnesium found in cobalt stannate samples from various works of Renoir and Caillebotte. This has not been documented for paintings of this time period and thus it is important to understand the role of magnesium in these pigments. The goal of this project is to investigate how magnesium affects the visual and materials properties of the pigments. More specifically, the objective is to characterize the chemistry, structure, and material properties of the cobalt stannates. We used characterization techniques like Fourier transform infrared spectroscopy (FTIR), energy dispersive x-ray spectroscopy (EDS) on the scanning electron microscope (SEM), Raman spectroscopy, and x-ray diffraction (XRD). Characterization on various reference cobalt based blue pigments such as paint outs, powder pigments, and samples from the paintings revealed interesting results. FTIR showed that cellulose nitrate was the binder, in contrast to the reference book label that stated they were oil colors. EDS and Raman revealed a combination of cobalt stannate and cobalt aluminum spinel particles within the cobalt stannate samples. These results have led us to look further into other techniques, like x-ray diffraction, to observe the effect on the structure due to the presence of magnesium in the cobalt stannate samples. We will look into alternative sample preparation methods for xray diffraction. The investigation of cobalt based blue pigments will aid in the conservation and restoration of intricate and valuable paintings from this time period, as well as provide a better understanding of art history, artist’s materials, and manufacturing processes.
Funder Acknowledgement(s): Materials Research Science and Engineering Center under NSF grant DMR #1121262. This work made use of the EPIC facility (NUANCE Center-Northwestern University), which has received support from the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); and the State of Illinois, through the IIN.
Faculty Advisor: Francesca Casadio,