Photoregulative phase change biomaterials showing thermodynamic and mchanical stabilities

Azobenzenes are great photochromic molecules for switching the physical properties of various materials via trans-cis isomerization. However, the UV light resulted cis-azobenzene is metastable and thermodynamically gets back to trans-azobenzene after ceasing UV irradiation, which causes an unwanted property change of azobenzene-containing materials. Additionally, thermal and mechanical conditions would accelerate this process dramatically. In this present work, a new type of azobenzene-containing surfactant is designed for the fabrication of photoresponsive phase change biomaterials. With a locked cis-azobenzene conformation, the resulting biomaterials could maintain their disordered state after ceasing UV light, which exhibit great resistance to thermal and piezo conditions. Interestingly, the locked cis-azobenzene could be unlocked by Vis light in high efficiency, which opens a new way for the design of phase change materials only responding to light. By showing stable cis-azobenzene maintained physical state, the newly fabricated biomaterials provide new potential for the construction of advanced materials, like self-healing materials, with less use of long time UV irradiation for maintaining their disordered states.

Automated summary

A new type of azobenzene-containing surfactant is designed for the fabrication of photoresponsive phase change biomaterials, providing better stability and resistance. The locked cis-azobenzene can be efficiently unlocked by visible light, offering a new approach for designing phase change materials only responsive to light.