The Anion Binding Affinity Determines the Strength of Anion Specificities of Thermosensitive Polymers

In this work, we demonstrate that the strength of anion specificities of thermosensitive polymers is determined by the affinity of direct anion binding to the polymers. We have prepared a series of thermosensitive statistical copolymers with distinct thermoresponsive behaviors. The anions can specifically interact with the different types of thermosensitive polymers in very different strengths. A similar strength of specific anion effects on thermoresponsive behaviors can be observed at very different salt concentrations for the different types of thermosensitive polymers. A stronger anion binding to the thermosensitive polymers gives rise to a more obvious anion specificity and vice versa. The work presented here opens up opportunities for the application of ion binding affinity to modulate the strength of ion specificities of thermosensitive polymers.