Hybrid κ-carrageenan-based polymers showing "schizophrenic" lower and upper critical solution temperatures and potassium responsiveness.

•Polymers exhibit both lower and upper critical solution temperatures.•Limit temperatures can be easily adjusted by grafts length and grafting density.•Polymer behavior is additionally dependent on the concentration of potassium ions.•Polymers are useful in applications requiring thermo- and potassium-responsivity.