Light and Shape‐Memory Polymers: Characterization, Preparation, Stimulation, and Application

Abstract

Shape‐memory polymers (SMPs) are smart materials that change shape when exposed to stimuli and have various applications in different fields due to their unique properties. Light, as a kind of electromagnetic radiation, plays an important role in understanding the structure‐property relations of SMPs, preparing original shapes, using them as non‐contact stimuli sources, and tuning the optical properties of SMPs. This review provides a comprehensive review of the involvement of light in structure‐preparation‐stimuli‐application of SMPs. The review is divided into four sections. First, applications of optical/spectroscopic approaches that provide information for understanding structure‐property relations in SMPs, especially during programming and recovery. Second, describes how to build SMPs with light, including different photochemical reactions and 3D photocuring technologies. Third, discusses how light is used to trigger the shape change of SMPs through both photochemical and photothermal mechanisms. Last, focuses on how to take advantage of the shape‐memory effect to tune the optical characteristics of polymers, including various structures of SMP color‐changing materials and their synthetic strategies. Future research could focus on developing efficient photothermal fillers, new 3D printing techniques for SMPs, exploring their use in biomedical and wearable devices, and optimizing SMPs for industrial applications.

Eco-Friendly Flame-Retardant Phase-Change Composite Films Based on Polyphosphazene/Phosphorene Hybrid Foam and Paraffin Wax for Light/Heat-Dual-Actuated Shape Memory

“…In contrast to inorganic foams, the utilization of elastic polymer foams as support materials for organic PCMs can endow the resultant phase-change composites with shape memory properties. This may expand the application of the phase-change composites into soft actuators and control devices. − According to the phase-transition and thermoviscoelastic theories, shape memory materials have two structural components, i.e., the reversible switching phase and permanent phase, , which can serve as adaptive programmable materials for flexible devices. , Solid–liquid PCMs can act as the reversible switching phase to drive shape memory transitions through solid–liquid phase changes. When the environmental temperature is higher than the melting temperature ( T m ) of a solid–liquid PCM, the PCM is melted to obtain a softened state, resulting in its deformation to a certain shape.…”

Optical and physical properties of zirconium dioxide reinforced poly(methyl methacrylate) nanocomposite films

“…This is much important in light receivers like, eyes, solar cells, cameras, etc. 13 In many of the opto-electronic applications, where, the light to energy conversion and vice versa is important, is of great importance to tailor make the refractive index of the materials so as to reduce the refractive index mismatch between materials. This is to reduce the scattering at the boundaries of layers and thus enhance the light to energy conversion, be it in the case of light emitting diodes where the energy is converted to light or be it in the case of Solar cells where light is converted to energy.…”

Photoresponsive Block Copolymer Nanostructures through Implementation of Arylazopyrazoles

“…Many photoresponsive BCPs exhibit a shape transition in the solid state, − or their transitions in solution are based on supramolecular interactions, such as host–guest complexes. − In comparison, fewer examples exist on the self-assembly of BCPs with photoresponsive blocks in solution. In one prominent example, Wang et al studied an alternating azo copolymer that can undergo a photoinduced deformation .…”