A thermoresponsive polymeric nanohydrogels has been synthesized by inverse microemulsion polymerization of N-isopropylacrylamide (NIPA) and acrylic acid (AAc) using Aerosol (AOT) as a surfactant, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, and 2,2'-azobisisobutyronitrile (AIBN) as initiator. The effect of concentration of AIBN, EGDMA, and NIPA/AAc weight ratio was investigated. The lower critical solution temperature (LCST) of poly (NIPA-co-AAC) can be manipulated to be 40 degrees C and 45 degrees C which was correlated to amount of AAc that was copolymerized with NIPA. FTIR, 1H NMR, TEM, and DSC characterized the nanohydrogels. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012