Effect of aqueous glycine treatment on the fine structure and dyeing ability of cotton

Exhaustion dyeing of cotton means a significant proportion of dyestuff is not fixed onto the material and is drained out when the dyebath is emptied. This waste presents issues for dye houses in terms of remediating water quality and the loss of expensive dye chemicals. Work to improve the dyeing ability of cotton has been limited to modifying cotton's cellulose structure by, notionally, environmentally hazardous treatments, e.g., concentrated caustic soda. Here we use a buffered, aqueous glycine treatment to improve the dyeing ability of cotton. The treated cotton showed improved dye absorption compared with control samples. An investigation of the structure of the treated cotton using Fourier Transform Infrared spectroscopy (FTIR) and 13C solid-state nuclear magnetic resonance (NMR) showed there was no appreciable change in crystallinity. However, there were changes in the chemical structure of the glycine-cellulose complex that were related to the pH of the buffered glycine treatment.