Halochromic properties of a 5-aminoimidazole-4-carboxamidrazone and its application to wool

Abstract

The application of stimuli-responsive molecules in textiles is an important field due to its potential in various areas of flexible sensing technology. In particular, pH plays an important role in nature, humans, and several processes. The pH of body fluids is one of the best indicators of disturbed health conditions. Thus, the development of textiles with halochromic properties has been increasingly attractive to display in real-time pH variations. Wool is one of the most important natural fibres because of its warmth and comfort. However, the dyeing process is costly and high energy-consuming. In this work, the halochromic properties under different buffers (acetate, phosphate, Britton-Robinson, artificial sweat, and artificial wound exudate) of a previously synthesized 5-aminoimidazole-4-carboxamidrazone were studied. Moreover, the first attempt to dye a wool knitted fabric with this molecule at a low temperature was performed. The developed material showed interesting halochromic properties (colourless in acidic pH and blue colour in the alkaline pH), even using artificial body fluids.