纳米二氧化硅改性不锈钢网用于油水分离

The nano-silica modified stainless steel mesh for oil-water separation

摘要:

采用了分步沉积和原位生长法来制备一种超亲水-水下超疏油不锈钢网（SSM-PDA-SiO2），用于重力驱动油水分离。在经过聚多巴胺（PDA）修饰的不锈钢网上原位生长了纳米二氧化硅（SiO2），从而使其具有超亲水-水下超疏油性质。研究通过使用FT-IR、XRD、TG、SEM和接触角测量仪等方法对改性不锈钢网的化学成分、微观形貌和湿润性进行表征。实验结果显示，经过八小时硅溶胶的加入，得到的SSM-PDA-SiO2具有最大的水下接触角（159.6°）和最小的滚动角（5°），表现出超亲水-水下超疏油性质。改性不锈钢网的首次分离通量达到40165 Lm-2h-1，分离效率为99.3%。即使在进行了50次分离循环后，仍然具有17728 Lm-2h-1的通量和98%的分离效率，显示出良好的循环利用性。此外，经过35次砂纸磨擦循环后，改性不锈钢网仍然保持了98%以上的分离效率，具良好的力学稳定性。

Abstract:

A superhydrophilic-underwater superoleophobic stainless steel mesh (SSM-PDA-SiO2) was prepared using a stepwise deposition and in-situ growth method for gravity-driven oil-water separation. Nano-sized silica (SiO2) was grown in situ on a polydopamine (PDA) modified stainless steel mesh to impart superhydrophilic-underwater superoleophobic properties. The chemical composition, morphology, and wettability of the modified stainless steel mesh were characterized using techniques such as FT-IR, XRD, TG, SEM, and contact angle measurement. The experimental results showed that the SSM-PDA-SiO2 obtained after eight hours of silica sol addition exhibited the highest underwater contact angle (159.6°) and the lowest rolling angle (5°), demonstrating superhydrophilic-underwater superoleophobic properties. The modified stainless steel mesh achieved an initial separation flux of 40165 Lm-2h-1 with a separation efficiency of 99.3%. Even after 50 separation cycles, it still maintained a flux of 17728 Lm-2h-1 and a separation efficiency of 98%, indicating good recyclability. Additionally, after 35 cycles of sandpaper abrasion, the modified stainless steel mesh retained a separation efficiency of over 98%, demonstrating good mechanical stability.