The preparation and application of functional hydrogels based on natural polysaccharides have always been a hot research topic. In this study, using acrylamide (AM) monomer, N, N'-methylene bisacrylamide (MBA) as cross-linking agent, potassium persulfate (K2S2O8) as initiator, in the presence of natural polysaccharide sodium alginate (SA), the PAM/SA hydrogel was prepared by free radical polymerization. Fourier transform infrared spectroscopy (FT-IR), swelling performance tests, scanning electron microscope (SEM), thermogravimetric analysis (TGA), UV-visible spectrophotometer, mechanical property measurements were carried out to analyze the composition, morphology, and performance of the hydrogels. The swelling behavior, dye adsorption performance, and the mechanical properties of PAM/SA hydrogels before and after Fe3+ adsorption were studied. The experimental results showed that the introduction of SA with 4.7%, 7.8%, and 10.3% effectively improved the mechanical and dye adsorption properties of PAM composite hydrogels. The adsorption capacity of PAM/4.7%SA and PAM/10.3%SA hydrogels at equilibrium can reach 40.01 and 44.02 mg/g for methylene blue, which is higher than the value 13.58 mg/g of pure PAM hydrogel. The compressive strength of pure PAM hydrogel is 0.124 MPa. When the SA content is 4.7%, 7.8%, and 10.3%, the compressive strength of the PAM/SA hydrogel was corresponding to 0.130 MPa, 0.134 MPa, and 0.152 MPa, respectively. Fe3+ was introduced into the PAM/SA hydrogels, and PAM/SA/Fe3+ double-network hydrogels with excellent mechanical properties could be prepared by adjusting the SA content (4.7%, 7.8%, and 10.3%), soaking time (1 h, 2 h, 3 h, 4 h, 5 h, 6 h), and Fe3+ concentration (4.76%, 7.41%, 9.09%, and 13.04%). Under the same Fe3+ concentration of 9.09% and adsorption time of 4 h, the compressive strengths of the PAM/4.7%SA, PAM/7.8%SA, and PAM/10.3%SA hydrogels could reach 0.354 MPa, 0.767 MPa, and 0.778 MPa, respectively.
}, DOI = {10.32604/jrm.2021.015593} }