Synthesis and characterization of novel D‐mannitol based hydrogel: Swelling and adsorption behavior of heavy metal ion studies

Abstract

A highly efficient hydrogel derived from D‐Mannitol xanthate has been successfully synthesized using a free‐radical solution copolymerization technique. An equimolar mixture of acrylonitrile (AN) and acrylic acid (AA) has been reacted with D‐Mannitol xanthate (DMX) under inert atmosphere. Three distinct grades of D‐Mannitol xanthate‐based hydrogels viz. DMXHGs‐1, DMXHGs‐2, and DMXHGs‐3, were prepared. Extensive analyses were conducted on the hydrogels using various methods such as UV, FT‐IR, SEM, XRD, GPC, TGA and ΔpHPZC. The maximum swelling ratio of DMXHGs‐3 was found to be 52122%, 50434% and 48576% for 24 h with water retention ratio of 80.98%, 78.64% and 79.22% for 30 h in distilled, tap and gray water respectively. These findings indicate the DMXHGs‐3 hydrogel has remarkable swelling and water retention capacity. Comprehensive investigations were carried out to evaluate the hydrogel's remarkable adsorption capacity to act as an adsorbent for effectively removing hazardous metal ions. The highest removal percentages of 95.5% and 94.4% and maximum adsorption capacities of 523.56 mg g−1 and 462.96 mg g−1 were observed with DMXHGs‐3 hydrogel for Cu2+ and Co2+ ions, respectively. Metal ion removal experiments were conducted by varying several parameters including dosage, pH, temperature, concentration, and time. The quantification of Cu2+ and Co2+ was accomplished using UV–visible spectroscopy. Present studies demonstrate the suitability of D‐mannitol xanthate‐based hydrogels for the efficient removal of toxic metal ions from wastewater.