Comparative Analysis of Hydrogel Adsorption/Desorption with and without Surfactants

Abstract

In this study, the hydrogel (SAP-1) was prepared by grafting acrylic acid-co-acrylamide onto pullulan (Pul-g-Poly (acrylic acid-co-acrylamide)) and the sponge hydrogel (SAP-2) was prepared by adding the surfactant sodium dodecyl benzene. sulfonate (SDBS) by free radical solution polymerization. Several properties were used to determine the efficiency of the prepared hydrogels such as Fourier transform infrared spectroscopy, hydrogen nuclear magnetic resonance (1H NMR), atomic absorption spectroscopy, and field emission scanning electron microscopy (FE-SEM) to further understand the composition and properties of the hydrogels. On the other hand, the absorption kinetics were studied and analyzed with the experimental equilibrium capacities of the prepared hydrogels were determined. The results demonstrated that each of the prepared hydrogels is an effective adsorbent of cadmium (II), copper (II), and nickel (II) ions. SAP-2 gel is characterized by its high ability to absorb cadmium (II) ions at a rate of 190.72 mg/g, followed by SAP-1 gel for absorbing cadmium (II) ions at a rate of 146.9 mg/g and copper (II) ions at a rate of 154 mg/g. The hydrogel (SAP- 2) with its high ability to repeat the adsorption-absorption cycles 3 times for cadmium (II) ions, the absorption capacities were 190.72 mg/g, 100.43 mg/g, and 19.64 mg/g at first, second, and third cycles, respectively. Based on the above results, all the prepared hydrogels are good candidates for adsorption and desorption of cadmium (II), copper (II), and nickel (II) ions.