In this study, it has been investigated that the incorporation of poly(ethylene glycol), (PEG) and 4-styrenesulfonic acid sodium salt, (NaSS) into acrylamide, (AAm) hydrogel during free radical solution polymerization synthesis. Poly (ethylene glycol)dimethacrylate, (PEGDMA) was used as a multifunctional crosslinker in polymerization. The main purpose of this study was to combine both monomers and a polymer in a new polymeric system. Dye sorption properties of hydrogels and semi IPNs were investigated by using cationic dye such as Union Green B (Janus Green B, UGB). Swelling and sorption studies were carried out at 25 degrees C. For structural characterization, FTIR analysis was made. The equilibrium percentage swelling (Seq%) ranges are 6601330% for AAm/NaSS hydrogels and 5801310% for AAm/NaSS/PEG semi IPNs. To determine the sorption behaviors of cationic dye UGB, some sorption parameters such as sorption capacity (q), adsorption percentage (Ads%) and partition coefficient (Kd) of the hydrogels were investigated. Binding characterization has been studied by Langmuir linearization method. The sorption capacity values of the hydrogel systems were changed between 1.24 x 104 and 4.05 x 104 mol g1. The values of Ads% of the hydrogels were changed among 1867%, and the values of Kd of the hydrogels were between 0.22 and 2.02. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers