Synthesis and characterization of novel and smart hydrogels for uranyl ions uptake under saline conditions

In the present paper we report the synthesis and characterization of two copolymeric hydrogels based on acrylic acid (AAc) and methacrylic acid (MAAc) with acrylamide (AAm) for use in the removal and sorption of the uranyl ions from saline conditions. In a novel research plan, the hydrogels were synthesized by polymerizing AAm separately with equimolar amount of AAc and MAAc using ammonium persulphate (APS) as initiator and ethylene glycol dimethacrylate (EGDMA) as crosslinker to get crosslinked bifunctional hydrogels namely poly(AAm-co-AAc) hydrogel and poly(AAm-co-MAAc) hydrogel respectively. The hydrogels are bifunctional and have both amide and acid functional groups. For comparison, reference poly(acrylic acid) hydrogel [Poly(AAc) hydrogel] and poly(methacrylic acid) [Poly(MAAc) hydrogel] were also prepared. The hydrogels were characterized by nitrogen analysis, FTIR and SEM. Swelling studies of hydrogels were carried out as a function of time, temperature, pH and in 5% NaCl solution. These hydrogels respond quickly to the changes in their external environment and are pH and temperature sensitive and moderately salt tolerant. These hydrogels have been successfully used for uptake of uranyl ions from saline conditions. Uranyl ion uptake was studied as a function of concentration of uranyl ions in the presence of 0.1 N Na2CO3 and three different concentrations of NaCl (1%, 2% and 3%) for three different time intervals (1h, 2h and 4h) at 25oC to 45oC. It is very interesting to observe that even in the presence of strong electrolytic salts percent swelling and percent uptake of uranyl ions is appreciable thereby indicating the salt tolerance of the hydrogels

Author(s): Sandeep Chauhan1 and Nitika Chauhan2

Abstract | PDF

Share This Article