Facile Synthesis and Fabrication of NIPAM-Based Cryogels for Environmental Remediation

Herein, polymeric cryogels containing poly(N-isopropylacrylamide) were synthesized by cryo-polymerization at subzero temperature. The synthesized cryogels were loaded with silver and palladium nanoparticles by the chemical reduction method at room temperature using the reducing agent NaBH4. Moreover, for comparison with cryogels, pure poly(N-isopropylacrylamide) hydrogel and its silver hybrid were also prepared by the conventional method at room temperature. The chemical structure and functional group analysis of the pure cryogels was confirmed by Fourier transform infrared spectroscopy. The synthesis of hybrid cryogels was confirmed by the X-ray diffraction technique and energy dispersive X-ray. The pore size and surface morphology of the pure cryogels, their respective hybrid cryogels and of conventional hydrogels were studied by using the scanning electron microscopy technique. The hybrid cryogels were successfully used as a catalyst for the degradation of methyl orange dye. The degradation performance of the hybrid cryogels was much better than its counterpart hybrid hydrogel for methyl orange dye. The effect of temperature and amount of catalyst on catalytic performance was studied by UV-visible spectroscopy. The reduction follows pseudo-first-order reaction kinetics. In addition, the antibacterial activities of these cryogels were evaluated against Gram-positive bacteria (Staphylococcus aureus, ATCC: 2593) and Gram-negative bacteria (Escherichia coli, ATCC: 25922). Both hybrid cryogels have shown much better antibacterial activity for these two strains of bacteria compared to pure cryogels. The results indicate that these cryogels are potential candidates for water purification systems as well as biomedical applications.

Automated summary

Polymeric cryogels containing poly(N-isopropylacrylamide) were synthesized by cryo-polymerization at subzero temperature, and loaded with silver and palladium nanoparticles using the reducing agent NaBH4. The chemical structure of the cryogels was confirmed by Fourier transform infrared spectroscopy, and their synthesis was confirmed by X-ray diffraction and energy dispersive X-ray. The pore size and surface morphology of the cryogels were studied using scanning electron microscopy. The hybrid cryogels showed superior catalytic performance and antibacterial activity compared to pure cryogels, making them potential candidates for water purification systems and biomedical applications.