Stimuli-responsive polymers are capable of exhibiting reversible or irreversible changes in physical and/or chemical properties in response to small changes in external environment, such as pH, ions, temperature, light, etc. In recent years, stimuli-responsive polymers have been widely used in disease diagnosis, drug delivery, and sensors. Depending on the type of the external stimuli, stimuli-responsive polymers can be classified into several categories. This article reviews the synthesis methods and the mechanism of the stimuli-responsive polymers based on the chemical stimulation, physical stimulation and biological stimulation. Furthermore, the long-term prospect and the potential applications of these functional materials are introduced.
Contents
1 Introduction
2 Chemical stimulation
2.1 pH-responsive polymers
2.2 Gas-responsive polymers
2.3 Ion-responsive polymers
3 Physical stimulation
3.1 Thermo-responsive polymers
3.2 Electric-responsive polymers
3.3 Photo-responsive polymers
4 Biological stimulation
4.1 Glucose-responsive polymers
4.2 Nucleic acids-responsive polymers
4.3 Enzyme-responsive polymers
5 Conclusion