Photo-responsive Behaviors of Hydrogen-Bonded Polymer Complex Fibers Containing Azobenzene Functional Groups

Two azobenzene compounds, Disperse Red 1 (DR1) and 4-aminoazobenzene (Aazo), were separately linked to poly(acrylic acid) (PAA) side chains to form PAA-DR1 and PAA-Aazo, which were then associated with poly(ethylene oxide) (PEO) to produce hydrogen-bonded polymer complex fibers. After UV irradiation, the initial modulus and yielding strength of PAA-Aazo/PEO fiber were both increased tremendously, while the mechanical properties of PAA-DR1/PEO fiber only slightly changed. After drawn and dried in vacuum, PAA-DR1/PEO and PAA-Aazo/PEO fibers with an extended length exhibited a contraction of 20% and 25% under UV irradiation, showing potential for photo-actuation.

Automated summary

In this study, azobenzene compounds DR1 and Aazo were linked to PAA side chains to form PAA-DR1 and PAA-Aazo, which were then associated with PEO to produce hydrogen-bonded polymer complex fibers. UV irradiation led to significant improvements in mechanical properties for PAA-Aazo/PEO fibers, while only slight changes were observed for PAA-DR1/PEO fibers. Additionally, both types of fibers showed contraction under UV irradiation, indicating potential for photo-actuation.