Designing eco-friendly pH-responsive Azo dyes for sustainable textile fabrics

Area of Science:

• Textile Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Sustainable textile dyeing requires high-performance, eco-friendly colorants.
• Developing pH-responsive materials is crucial for advanced sensing applications.

Purpose of the Study:

• To synthesize novel disazo acid dyes for sustainable textile applications.
• To evaluate the dyes' performance in textile coloring and pH-responsive sensing.
• To investigate the structural and chromatic properties of the synthesized dyes.

Main Methods:

• Simplified diazotization-coupling reactions using sulphanilic acid and aromatic derivatives.
• Structural characterization to confirm azo and sulfonate group integration.
• Application testing on wool and nylon for color fastness and K/S values.
• UV-Vis spectroscopy and pH-titration to assess spectral properties and pH-responsiveness.

Main Results:

• Four disazo acid dyes (D1-D4) were successfully synthesized with excellent water solubility.
• Dyes exhibited bright orange and red hues on wool and nylon with high wash and light fastness (4-5).
• Dye D1 demonstrated a reversible color transition from brown to pink under acidic pH conditions, indicating pH sensitivity.

Conclusions:

• The synthesized disazo acid dyes offer high performance and eco-friendly characteristics for textile dyeing.
• Dye D1 shows significant potential for developing pH-sensitive smart fabrics and sensors.
• Wool substrates provided superior K/S and fastness properties compared to nylon, reducing environmental leaching.