Abstract
Invention of high-performance, environmentally friendly disazo acid dyes (D1-D4) intended for sustainable textile coloring and pH-responsive sensing applications is reported in this study. Sulphanilic acid and other aromatic derivatives were used in simplified diazotization-coupling procedure to create dyes. Effective integration of azo and sulfonate groups, guaranteeing superior water solubility, was verified by structural characterization. Dyes created bright, high-affinity orange and red colors with remarkable wash and light fastness (ratings: 4–5) when applied to wool and nylon. λmax values in UV-vis spectra varied according to substituent location, from 479 to 485 nm. Notably, protonation-deprotonation balance drives Dye D1’s reversible, “smart” color shift from brown to pink in response to pH changes. Among synthesized dyes, D1 showed a clear and reversible pH-responsive color change, going from brown to pink under increasingly acidic conditions, while D3 showed mild pH sensitivity and dyes D2 and D4 remained color-stable throughout tested pH range of 2–4, displaying distinct chromatic stability profiles. Compared to nylon, the K/S and fastness qualities of wool materials were higher. These results show that synthesized dyes have great promise for creation of novel, pH-sensitive smart fabrics in addition to offering excellent technical performance and high fixing, which reduces environmental leaching.
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Abbreviations
- Conc.:
-
Concentration
- Dyeings:
-
Dyed textile fiber
- ISO:
-
International organization of standard methods
- o.w.f:
-
Of weight of fiber
- Scoured fabric:
-
Fabric free from dirt, oils and fats
- λmax :
-
Wavelength of maximum absorption
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Acknowledgements
This work was supported by Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2026R398), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.
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***Conceptualization*** : Kiran Shahzadi; ***Methodology*** *:* Kiran Shahzadi and Muneerah Alomar; ***Data curation*** : Kiran Shahzadi, Muneerah Alomar, and Maryam Al Huwayz.; ***Software*** : Kiran Shahzadi, Muneerah Alomar, and Maryam Al Huwayz.; ***Validation*** : Kiran Shahzadi, Muneerah Alomar, Maryam Al Huwayz, and Muhammad Sarfraz.; ***Visualization*** : Kiran Shahzadi, Muneerah Alomar, Maryam Al Huwayz, and Muhammad Sarfraz.; ***Formal analysis*** : Kiran Shahzadi, Muneerah Alomar, Maryam Al Huwayz, and Muhammad Sarfraz.; ***Investigation*** : Kiran Shahzadi, Muneerah Alomar, Maryam Al Huwayz, and Muhammad Sarfraz.; ***Writing-original draft preparation*** : Kiran Shahzadi, Muneerah Alomar and Maryam Al Huwayz; ***Writing-review and editing*** : Kiran Shahzadi, Muneerah Alomar, Maryam Al Huwayz, Muhammad Sarfraz, and A.A. Adediran; ***Project administration*** : Kiran Shahzadi, Muneerah Alomar, and Maryam Al Huwayz. ***Resources*** : Kiran Shahzadi, Muneerah Alomar, and Maryam Al Huwayz. ***Funding acquisition*** : Kiran Shahzadi, Muneerah Alomar, and Maryam Al Huwayz. All authors have read and agreed to the published version of the manuscript.
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Shahzadi, K., Sarfraz, M., Alomar, M. et al. Designing eco-friendly pH-responsive Azo dyes for sustainable textile fabrics. Sci Rep (2026). https://doi.org/10.1038/s41598-026-35135-y
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DOI: https://doi.org/10.1038/s41598-026-35135-y
