Cooperative construction of oil/water separator using renewable lignin and PDMS

Super-hydrophobic materials have played a significant role in the oil/water separation field. The traditional super-hydrophobic materials are prepared by fluorine-containing materials. However, although fluorine-containing materials have lower surface energy, they are expensive and difficult to degrade. Therefore, it's a great challenge for the designed and prepared the super-hydrophobic porous materials with super-oleophilicity to explore an environmentally friendly, easy-to-operate, low-cost, and renewable separator for oil/water mixtures separation. In this work, taking advantage of the microscale of renewable lignin and the low surface energy of polydimethylsiloxane (PDMS), the porous super-hydrophobic sponge material with super-oleophilicity was prepared by the synergy of polydimethylsiloxane (PDMS) and lignin. After soaking and curing, the porous super-hydrophobic sponge showed a high apparent water contact angle which is up to 160°. The designed porous sponge materials can effectively absorb heavy oil in oil-water mixtures separation. Moreover, the porous sponge materials possess temperature stability, acid and alkali stability, and are easy easily recyclable. As high-efficiency oil-water separation material prepared by the synergy between renewable natural polymers and fluorine-free materials, this technique is not only conducive to remediate environmental problems but also helpful to explore the potentiality of lignin that seemingly bio-waste. At the same time, valuable oil can also be recycled.