Photochromic Materials: Design and Applications

Photochromism is a phenomenon described as a reversible conversion of a chemical species between two isomeric forms, induced by the absorption of electromagnetic radiation, which results in color changes. Isomerization of organic photochromic molecules involves chemical processes such as: pericyclic reactions, electron and intramolecular hydrogen transfers, cis-trans isomerization and photodimerization. Photochromic molecules have attracted considerable interest, mainly due to their essential properties and potential applications in stimuli-responsive materials. In particular, light is generally considered as one of the most attractive stimuli in controlling stimuli-responsive materials because it can provide remote control with high spatial and temporal precision.

Photochromic materials feature various properties on both microscopic and macroscopic levels upon the external stimulation and the photo-responses process may involve multiple photons and molecules. Organic photochromic materials have demonstrated to be fatigue resistant with structural diversities. This class of molecules have been widely investigated for its promising applications in security markings, ions and solvents probing, optical shutters, photo-switchable molecular devices, topographical change materials and optical memory storage systems. Several physical or chemical methods such as temperature, acidity, hydrogen bonding, ion-binding, chemical reactions and oxidation/reduction have been used to trigger or control the photochromic properties.

This Research Topic aims to present the latest developments in the fabrication of photochromic materials and their applications. We encourage publications combining theoretical and experimental approaches. One particular area of focus will be the challenges of reusing these materials based on their possible reversibility. This Research Topic will include but are not limited to the following research areas:

• Synthesis and characterization of photochromic systems.
• Physical and chemical property investigation of photochromic materials.
• Fabrication of nano and microstructures containing photochromic molecules, including fibers, films, particles and so on.
• Applications of photochromic materials (e.g.: sensing, metal ion binding, drug release, and tissue engineering).

Keywords: photochromic materials, stimuli-responsive material

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.