Vibrational spectroscopic applications for detecting of consolidated harakeke fibres in conservation

• Main Authors: Samanali, Garagoda Arachchige P., Paasi, I., Dunne, Henry, Lowe, Bronwyn J., Smith, Catherine A., Fraser-Miller, Sara J., Gordon, Keith C.
• Other Authors: Asian Spectroscopy Conference 2020
• Format: Conference or Workshop Item
• Language: English
• Published: 2020
• Subjects: Science::Chemistry; Raman Spectroscopy; Infrared Spectroscopy
• Online Access: https://hdl.handle.net/10356/144325
• Institution: Nanyang Technological University

Traditional Māori textiles are mostly composed of harakeke fibres (Phormium tenax, New Zealand flax) and coloured by various natural dyes. Fibres are dyed black (paru) with iron tannate compounds [1]. These textiles are liable to degradation which is believed to occur via acid catalysed hydrolysis and iron catalysed oxidation [1, 2]. To mitigate this degradation, these textiles are treated with different consolidants. There is however a poor understanding of the mode of action of consolidants at a molecular level. In this study, paru dyed and non-dyed harakeke fibre samples treated with the common consolidants; sodium alginate, zinc alginate, Paraloid B-72™, TriFunori™, and MethocelA4C™ were assessed by bulk Raman and infrared (IR) spectroscopic techniques. These consolidated fibers were artificially aged using light ageing to evaluate for potential protective effects from the consolidants [3]. Also, non-dyed, consolidated fibres were studied by Raman microscopic analysis to detect the consolidant distribution within the sample. These data were analysed using; band integrals analysis, principal component analysis, and true component analysis, was applied to understand subtle variances in the samples of bulk and microscopic analysis (Fig. 1).