Tuning the thermochromism of water-soluble poly(3-thiopheneacetic acid) conjugated polymer by complexation with zwitterionic polymer

The spectral properties and phase behavior of the complexes of the water-soluble poly(3-thiopheneacetic acid) (P3TAA) conjugated polymer with zwitterionic 3-dimethyl(methacryloyloxyethyl) ammonium propane sulfone (PDMAPS) polymer were explored. A dramatic change in both electronic spectra and upper critical solution temperature (UCST) of P3TAA-PDMAPS complex solution was observed depending on the molar ratio of P3TAA and PDMAPS, suggesting that a conformational transition due to complexation occurred. The UV–vis λmax of P3TAA-PDMAPS complex solutions was changed dramatically in a narrow temperature range around a UCST and found to be varied over approximately a 40 nm range by the temperature change of about 20 °C.