Tailoring Nanostructured Dyes for Auxiliary Free Sustainable Leather Dyeing Application

Tailoring the dye functionality by nanoparticle structures offers a new opportunity for a sustainable leather dyeing process in the way of an auxiliary free dyeing process irrespective of substrate charge. Encapsulated nanoparticles, which are nanocages from a polymeric silicalike material, have been widely exploited as a template to guide the fabrication of nanostructures, because of their homogenized particle size, easy functionalization, and preparation through a viable route. In this work, functional rich and pH stable dye-encapsulated nanostructured dyes were used as dyeing agents with commercial use in mind. Due to its uniform particle size (50 nm) and surface potential (−48.7 ± 1 mV) over different pH ranges, the fabricated dyeing system showed uniform penetration and fixation irrespective of the different stages of leather processing at different conditions. Thus, the integration of compatibility and ready absorption by proteins provides a practical way to resolve the problem of intensity variation and improper dyeing characteristics of an industrial scale dyeing system. A cost–benefit analysis was also done to study the economic viability of the newer dyeing system. Avoiding auxiliaries and using less dye makes this new dyeing system economically and environmentally beneficial as compared to tradition dyeing. These results demonstrate the flexibility of different dyes in nanoparticle encapsulation and provide new clues for the sustainable leather dyeing process.