Effect of Superabsorbent Polymer Hydrogels in the Advancement of Cementitious Materials– A Review

Super absorbency is the extraordinary capacity of a substance to absorb and retain a large amount of liquid. Hydrophobic polymer chains are cross-linked to form superabsorbent polymer (SAP) hydrogels. Due to greater ability to absorb water, extended lifespans, and availability of a wide range of basic chemical resources, synthetic hydrogels gradually displaced natural hydrogels. These superabsorbent polymer hydrogels are in usage around the world in various applications for more than 50 years. Hydrogels are referred to as intelligent or smart materials since they respond to certain environmental stimuli and undergo a large volume phase shift in response to specific physical and chemical stimuli. The various forms of hydrogels and their wider applications are currently of research interests. The main goal of this review is to assess the literature on the various classification systems for hydrogels, their physical and chemical properties, and the technical viability of using them in civil engineering applications based on the newest publications in this field and the role of hydrogels as a new building material promoting environmental sustainability. A newly developed class of the most recent hydrogel material generations was also briefly discussed. Graphical abstract on superabsorbent polymers in cementitious materials