Using Azo-Compounds to Endow Biobased Thermosetting Coatings with Potential Application for Reversible Information Storage

Abstract

Current progress on biobased thermosetting epoxy focuses on developing high thermomechanical properties. However, its functional applications that represent a significant subject for future trends have been rarely reported. This work provides an inexpensive and facile approach to fabricate photoresponsive biobased thermosetting coatings. We synthesized an itaconic acid-derived epoxy resin and graft azobenzene derivatives with acrylic double bonds onto the resin through a carbon− carbon coupling reaction initiated by ultraviolet irradiation. The azo-containing resin was coated onto different substrates and fully cured, showing a pencil hardness of 5H and adhesion of 5B. Ultraviolet-and blue light illumination efficiently modulated the reversible trans-to-cis transition of azo-moieties to endow the coating with excellent photochromic properties, including high color contrast and resolution, >100 print−erase cycles, and durability under daylight. The photochromic bio-resourced coatings fabricated by an inexpensive and facile strategy represented a promising candidate for commercialized reversible information storage to address sustainability concerns in the information-explosion era.

Fluorescent Azobenzene-Containing Compounds: From Structure to Mechanism

“…Since the discovery of azobenzene's isomerization in 1937 [1], it has shown great potential for use in liquid crystals [2][3][4][5][6][7][8], sensors [9][10][11][12][13], molecular photoswitches [8,[14][15][16][17][18], information storage [19][20][21], etc. due to its unique and remarkable properties, including the ability to undergo reversible cis-trans isomerization upon photo-irradiation at specific wavelengths.…”