Themed collection Stimulus-responsive polymers

Peter J. Roth and Andrew B. Lowe introduce this themed issue for Polymer Chemistry on stimulus-responsive polymers.

In this mini-review, we discuss multi-stimuli-responsive polymers, which exhibit upper critical solution temperature (UCST) behavior mainly in aqueous solutions, and focus on examples where counter ions, electricity, light, or pH influence the thermoresponsiveness of these polymers.

Stimuli-responsive polymers respond to a variety of external stimuli, which include optical, electrical, thermal, mechanical, redox, pH, chemical, environmental and biological signals. This paper is concerned with the process of forming such polymers by RAFT polymerization.

This review summarizes pH-responsive monomers, polymers and their derivative nano- and micro-structures including micelles, cross-linked micelles, microgels and hydrogels.

Responsive polymer-based materials are capable of altering their chemical and/or physical properties upon exposure to external stimuli. This review highlights their use for sensing and biosensing, drug delivery, and artificial muscles/actuators.

Materials which respond to biological cues are the subject of intense research interest due to their possible application in smart drug delivery vehicles.

Recent advances in field-responsive polymers, which have emerged as highly promising materials for numerous applications, are highlighted.

Recent advances in thermoresponsive poly(2-oxazoline)s, polypeptoids, and polypeptides, with a specific focus on structure–property relationships, self-assembly, and applications, are reviewed.

Photo-responsive polymers are able to change their structure, conformation and properties upon light irradiation.

This paper reviews the chemical fundamentals of CO₂-responsive polymers as well as the latest reported “smart” material systems switched by CO₂.

Key to the widespread application of smart polymers in drug delivery is understanding the mechanistic interplay, as well as consequence, of the presence of these macromolecules within living systems.

Modulating the thermo-responsive behaviour of poly(sulfobetaine methacrylates) whereby small structural changes cause big effects but show little logic.

Mechanical damages are able to induce formation of reactive groups, which with a proper catalyst, will lead to self-healing.

Double-networks based on amphiphilic polymer conetworks synthesized using RAFT polymerization were prepared, exhibiting pH-responsiveness, nanophase separation and enhanced mechanical properties.

The MDI phase in SMPUs develops a framework with netpoints evolving from spheres, to linked-spheres, linked-cylinders, and then to linked-bi-crossing-cylinders.

The effects caused by photo-induced proton generation on the assembly formation of dual-temperature/pH-responsive block copolymers are investigated.

A twin-netpoint-switch structure model for animal hair has been proposed for interpreting different shape memory abilities when exposure on different external stimuli, where a twin-netpoint/single-switch structure is for the stimulus of water, heat and UV-light, and a single-netpoint/twin-switch structure is for the stimulus of redox agent.

Self-assembled thermoresponsive polymers in aqueous solution have great potential as smart, switchable materials for use in biomedical applications.

Morpholine-functionalised poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) diblock copolymer vesicles are transformed into worms or spheres on lowering the solution pH.