Preparation of PEI-PAA/PDMC IPN Superhydrophilic Composite Hydrogels and Their Multifunctional Application in Wastewater Treatment

Polyacrylic acid has a wide range of applications in the field of superhydrophilicity, but due to its single composition, there are problems such as insufficient mechanical strength and functional limitations. In order to extend its application, we prepared a new IPN hydrogel PEI-PAA/PDMC. The results show that the new hydrogel loaded on different substrates (stainless steel mesh/filter cloth) possesses superhydrophilicity (WCA < 10°) and underwater superoleophobicity (OCA > 150°). The hydrogels not only separated oil–water mixtures with high throughput and efficiency (98%, 12,000 L m −2 h −1 ), but also separated oil-in-water emulsions by gravity alone (95%, 700 L m −2 h −1 ). Due to the large number of quaternary ammonium groups in the DMC, we have tested the antimicrobial properties of the DMC with excellent results (99.2% inhibition). Compared with previous studies, this paper introduces that PEI has the ability to adsorb heavy metals, and we tested Cu 2+ and found that the adsorption and separation efficiency reached 75%. This study provides new ideas for the direction of wastewater treatment.