The first (G1) and second generation (G2) of dendronized copolymers carrying solvatochromic dyes were synthesized, and their thermoresponsive properties investigated. These copolymers were constituted with oligoethylene glycol (OEG)-based dendrons to afford the thermoresponsiveness and disperse red 1 to act as the dye probe. The possible architecture and structure effects on sensoring were investigated by changing dendron generation from G1 to G2, and the interior structures of G2 polymers from hydrophilic OEG into hydrophobic alkyl chain. The sensoring ability of these copolymers to temperature and solution pH was examined with UV/Vis spectroscopy. Combined with the supports from fluorescence spectroscopy, remarkable thickness effects of dendronized polymers were discovered on the transitions of the dye moieties during the thermally-induced aggregation process. This work enriches the field of thermoresponsive colorimetric polymeric sensors, and provides an in-depth understanding of state changes of the dye probe during the thermally-induced phase transitions within these bulky dendronized polymers. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1706-1713