Water pollution has become a serious problem in aquatic ecology due to the oil spills and the consistent release of industrial pollutants, such as dyes. Herein, we report a simple method to fabricate superwetting caffeic acid (CA)-polyethyleneimine (PEI)-modified melamine sponges (CA-PEI-MS) for oil-in-water emulsion separation and dye adsorption. The as-fabricated CA-PEI-MS exhibited superhydrophilicity with an approximately zero water contact angel (WCA) and underwater superoleophobicity with an underwater oil contact angel (UWOCA) greater than 150°. The compressed CA-PEI-MS showed an excellent oil-in-water emulsion separation performance with a separation efficiency greater than 97% and a water flux of up to 25,480 L h⁻¹ m⁻² bar⁻¹. The recyclability test was used to study the stability of the compressed CA-PEI-MS, after washing with acetone; the flux did not show any significant change during the 12-cycle separation test. The separation efficiency in every cycle was greater than 97%. Due to the availability of rich positive charged amino groups, the as fabricated CA-PEI-MS exhibited adsorption ability towards negatively charged dyes such as, rose bengal (RB) and direct red (DR) with 96% adsorption efficiency. Therefore, the as designed low-cost and eco-friendly preparation of CA-PEI-MS has a great potential for practical application as it shows high separation performances and excellent efficiency.

由于漏油和染料等工业污染物的不断释放，水污染已成为水生生态中的一个严重问题。在这里，我们报告了一种简单的方法来制造超润湿的咖啡酸（CA）-聚乙烯亚胺（PEI）改性的三聚氰胺海绵（CA-PEI-MS），用于水包油乳液的分离和染料的吸附。制成的CA-PEI-MS在接近零水接触角（WCA）时表现出超亲水性，而在水下油接触角（UWOCA）大于150°时表现出水下超疏油性。压缩后的CA-PEI-MS具有优异的水包油乳液分离性能，分离效率大于97％，水通量高达25,480 L h ^-1 m ^-2 bar ^-1。用丙酮洗涤后，可循环性测试用于研究压缩的CA-PEI-MS的稳定性。在12个周期的分离测试中，通量没有显示任何明显的变化。每个循环中的分离效率均大于97％。由于可利用丰富的带正电荷的氨基，所制造的CA-PEI-MS表现出对带负电荷的染料（如玫瑰红（RB）和直接红（DR））的吸附能力，吸附效率为96％。因此，设计出的低成本，环保的CA-PEI-MS制备方法具有很高的分离性能和优异的效率，具有实际应用的巨大潜力。