Smart Photochromic Materials Triggered with Visible Light

Abstract

Molecular photoswitches reversibly convert the energy of light into a variety of structural changes at the molecular level. They can be integrated into smart materials with broad range of applicability. While most photochromic systems require UV light for activation, application of photoswitches operational entirely within the visible or NIR range of light brings considerable benefits, such as biocompatibility, better light penetration through the material, propelling with sunlight, or a possibility to design dual systems that are mutually activated with UV or visible light frequencies for two distinct functions. In this Review, we discuss the most relevant classes of molecular photoswitches, and demonstrate a selection of photochromic polymers, gels, porous materials, surfaces, energy-storing materials and other systems triggered with visible light.The main challenge in design of visible-light-triggered systems, including molecular switches, [21] is the fact that nonradiative [a] A.

Light-responsive bent-core liquid crystals as candidates for energy conversion and storage

“…Even though azobenzenes have been studied for several decades [5][6][7], they continue to attract interest due to their potential to promote long-range macroscopic changes induced by short-range molecular modifications. [8][9][10][11][12] Bent-core liquid crystals, BCLCs, exhibit anti-ferroelectric and ferroelectric behaviour with high figures of merit, which can be useful for energy storage applications. BCLCs can form columnar (Col, former B 1 ), polar smectic C (SmCP, former B 2 ), twist grain boundary dark conglomerate (DC) or helical nanofilament (HNF, former B 4 ) phases among others [13][14][15][16][17][18][19][20].…”

“…Even though azobenzenes have been studied for several decades, 5–7 they continue to attract interest due to their potential to promote long-range macroscopic changes induced by short-range molecular modifications. 8–12…”

Harnessing molecular isomerization in polymer gels for sequential logic encryption and anticounterfeiting

“…Most established photoswitches such as azobenzenes (35), spiropyrans (36), diarylethenes (37), and other photochromic motifs (38,39) have their isomerization triggered with high-energy UV light. While upon structural modifications, these can operate under visible light irradiation (40)(41)(42). DASAs are inherently triggered with visible light in their basic design, as well as water, to achieve complete isomerization (30,33,34,(43)(44)(45)(46)(47).…”

Rational Design of Smart Metal–Organic Frameworks for Light-Modulated Gas Transport

“…In many scenarios, photostimulation is applied, as light is abundant, clean, and nondestructive. The photoresponsive smart MOFs may play a key role in the energy-efficient and ecofriendly gas separation process. − …”