Thumbnail image of graphical abstract

A superabsorbent hydrogel composed of waste polystyrene, starch, and acrylic acid is prepared through emulsion polymerization, as presented by Hanafi Ismail, Maryam Irani, and Zulkifli Ahmad on page 4195. The hydrogel is characterized by SEM, FTIR spectroscopy, and TGA. The porosity of a hydrogel can affect its water absorbency and retention rate. Thus, one of the important properties to investigate is the hydrogel microstructure morphology. The image confirms that the prepared sample has a porous structure. These pores should provide regions for water penetration into the polymeric network and interaction sites for the hydrophilic groups of the polymer network and external stimuli.