Free radical polymerization of N,N-(dimethylamino)ethyl methacrylate and N,N-dimethyl-N-(methacryloyloxy)ethyl ammonium butane sulfonate was carried out to prepare PDMAEMA and PDMABS. Proton nuclear magnetic resonance spectroscopy indicated that both PDMAEMA and PDMABS exhibited an electrolyte-responsive conformational dynamics in D2O of different ionic strength. PDMAEMA, as a polybase, and PDMABS, as a polysulfobetaine, exhibited a series of multidimensional stimuli-responsive phase transition behaviors. Adding NaCl would decrease the phase transition temperature (T-PT) of their aqueous mixtures, because of polyelectrolyte effect for PDMAEMA and anti-polyelectrolyte effect for PDMABS, respectively. For PDMAEMA, a low pH would facilitate the dissolution; on the other hand, for PDMABS, a maximum TPT was achieved in neutral media. (c) 2007 Wiley Periodicals, Inc.