Dear Colleagues,

In recent years, many interesting studies on smart materials have been developed. Scientists are strongly inspired by nature to design smart materials that use biomimicry to emulate the behavior of living organisms and, by taking advantage of the ability of the material to interact with its surrounding, to provide an adaptive response to environmental changes. Among them, stimuli-responsive materials are attractive materials for a wide range of innovative applications in both technical industries (i.e., aeronautics, electronics, textile, and packaging) and the biomedical field (i.e., stents, scaffold, etc.), indicating their multidisciplinary character in materials science, chemistry, and engineering.

Smart polymers can be classified into the following three groups according to the stimuli they respond to: Physical—temperature, ultrasounds, light, electric or magnetic field or mechanical stress, etc.; Chemical—pH, ligands, and ionic strength, etc.; Biological—enzymes and biomolecules.

It is important to highlight that such responsiveness is not an intrinsic property of the material. It is obtained by properly designing the meso- or macroscopic arrangement of the constitutive elements or by the chemistry underlying the microstructure of the material. In particular, when the responsiveness at the molecular level is properly organized, the nanoscale response can be collectively detected at the macroscale, leading to a responsive material.

Different strategies have been used for the design of smart materials that can be triggered by several stimuli depending on the final applications. The responsiveness can be achieved by the introduction of either chemical or non-covalent bonds (i.e., photodimerization of coumarin, Diels–Alder reactions, supramolecular interactions, and dipolar interaction) or physical interactions, i.e., crystallites, glassy hard domains, hydrogen bonding, ionic clusters, chain entanglements, and interpenetrating networks. Additionally, smart polymers can be designed as “multimaterial” systems, such as multiblock copolymer and covalent polymer networks, as well as the preparation of blends from two or more polymers by a physical process. Despite their unique properties, the potential applications of smart polymers are often limited due to their low thermal conductivity, inertness to electrical stimulus, slow responsiveness to light and electromagnetic stimuli, and low recovery time during actuation. To overcome these difficulties, a new generation of smart polymeric nanocomposites can be designed. Generally, they are produced by the incorporation of one or more nanofillers, such as nanotubes, nanofibers, nanocrystals, etc., within the polymer matrix in order to increase their matrix properties, as well as to give them multifunctionality. However, it is important to point out that when a polymer presents a responsiveness to a trigger, it is not so trivial that its corresponding nanocomposites continue to show the same response at the same conditions. Therefore, many efforts are needed in this sense to obtain advanced smart polymeric nanocomposites.

This Special Issue in “Advances in Smart Polymers and Polymeric Nanocomposites” will bring together the more recent scientific achievements in the field of smart polymers and nanocomposites, focusing on the different strategies to design high-performance and multi-responsive materials.

Dr. Laura Peponi
Dr. Valentina Sessini
Guest Editor

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• smart materials
• stimuli-responsive materials
• shape memory properties
• shape memory nanocomposites
• multi-responsive polymers
• multifunctional polymers
• piezoelectric polymers and composites
• self-healing polymers and composites