Challenges in the preservation of contemporary couture - consolidation and protection of textiles with sol-gel silica coatings

Several haute couture contemporary textiles from museum collections exhibit serious conservation problems due to the high complexity of materials and production methods used in their conception. Conservation of contemporary textiles with new materials and production methods requires scientific research into the identification of materials and new conservation techniques. This was the case of the spectacular golden coat made by the French fashion designer Jean-Paul Gaultier, currently in MUDE (Museum of Fashion and Design), in Lisbon. The coat is an excellent example of Gaultier's eclectic selection of materials and technical versatility. It was created with a golden combined textile, with several attached golden polymeric and glass materials. Despite the importance of this piece, little information was available in the archives of MaisonGaultier. In order to understand the creative processes and identify the coat's materials that could provide important information for the stabilization and treatment of the piece, an interdisciplinary research was carried out. Characterization of the coat's materials with several analytical techniquesrevealed that the golden combined textile was apoly(ethylene terephthalate) canvas covered with apoly(dimethylsiloxane) (PDMS) layer and a yellow brass pigment hand-stitched to a yellow silk lining. The golden coat exhibits several pathologies, namely oxidation of the brass pigment and a significant deterioration of the PDMS layer due to humidity action. Indeed, the cohesion and adhesion properties of the PDMS layer are fragile inducing considerable material loss of the attached materials. The consolidation of the PDMS layer as well as its protection from a humidity environment was considered fundamental to stabilize the degradation of the golden coat. With a similar PDMS chemical nature, sol-gel silica was considered a potential candidate for a coating application in order to enhance the PDMS properties.Silica sols were prepared by the sol-gel method with tetraetoxysilane using ethanol, water and an acid and/or a base as catalyzers. Different additives were used to improve the PDMS properties such as hydrofobicity, flexibility and adherence. The films containing SiO2 were applied to test samples. Homogeneous thin films with few micro-cracks were obtained using spin coating and vapor-spraying on the film deposition. Moreover, minimal differences in pH and color were observed. The contact angle value improved slightly, indicating that the films exert in some extent a protection against the humidity. Further work is necessary to optimize the silica sol-gels process at room temperature and ensure that the film application will not change other coat properties.