<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: small;\"><span style=\"line-height: 150%;\">&nbsp;</span><span style=\"line-height: 150%;\">poly(N-isopropylacrylamide-co-itaconic acid) P(NIPAAm-co-IA) hydrogels </span><span style=\"line-height: 150%; color: #2e2e2e;\">were prepared </span><span style=\"line-height: 150%;\">using N- isopropylacrylamide (NIPAm) and itaconic acid (IA) as co-monomers.</span><span style=\"line-height: 150%; color: #2e2e2e;\">The influence of external stimuli such as pH and temperature of the swelling media on the equilibrium swelling properties was </span><span style=\"line-height: 150%;\">P(NIPAAm-co-IA) </span><span style=\"line-height: 150%;\">&nbsp;&nbsp;has been investigated for their pH and temperature dependent water upake behavior at room temperature and physiological temperature which was observed to be more and more pronounced at 37<sup>o</sup>C(physiological temperature). The water absorbency increased with itaconic acid content in the hydrogels at &nbsp;pH 4.</span></span></p>
<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: small;\">The equilibrium swelling ratios and deswelling/reswelling kinetics of the hydrogels were investigated under conditions of different pH and temperature. The result showed these hydrogels were able to absorb large amounts of water and exhibit improved temperature and pH sensitivities, which may be ascribed to the formed porous network</span><br /><span style=\"font-family: arial, helvetica, sans-serif; font-size: small;\"> structures. Their chemical structures, lower critical solution temperatures (LCSTs) and surface morphologies were also investigated by Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis and scanning electron microscopy (SEM).</span></p>
<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: small;\"><strong><span style=\"line-height: 150%;\">&nbsp;</span></strong></span></p>
<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: small;\">P(NIPAAm-co-IA) hydrogel <span style=\"line-height: 150%;\">&nbsp;has various application in the ground of biomedical &nbsp;and technological &nbsp;such as bioseparation, enzyme immobilization, tissue engineering and controlled drug delivery and are still developing for new promising applications. hydrogels are cross-linked materials absorbing large quantities of water without dissolving. Softness, smartness, and the capacity to store water make hydrogels unique materials. </span></span></p>
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