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In this study, pH sensitive poly (acrylic acid-co-acrylamide) [P(AAc-co-AM)] macroporous hydrogels hydrogels were successfully prepared by enhanced phase separation in the presence of 0.3,0.5 and 0.7mol/L aqueous sodium chloride (NaGl) solutions.The chemical compositions and structures of different hydrogels were similar, as measured by Fourier transform infrared spectroscopy (FT-IR).Analysis of the scanning electron microscopy (SEM) showed that the pore morphologies of these hydrogels were dependent on the concentration of NaCl and more macropores were observed in the samples prepared with higher NaCl concentration.Swelling studies showed an increase in equilibrium swelling ratio in distilled water as the NaCl concentration in the polymerization medium increased from 0 to 0.7mol/L.The P(AAc-co-AM) hydrogels exhibited stronger sensitivity to pH and ionic strength(Ⅰ), and showed much faster reswelling and deswelling response rates in the more NaCl concentration.These data implied that the addition of NaCl to the polymerization medium produced heterogeneous macroporous hydrogels of controlled morphology during the polymerizations.