Jibin Yang,Huicai Wang,Zhongan Tao,Xiaping Liu,Zhenwen Wang,Ruirui Yue,Zhanfeng Cui
Oil/water mixtures are easily converted into microemulsions with high stability and complex structures under the action of surfactant, causing great difficulties for effective separation. In this paper, we report a 3D porous melamine sponge with superhydrophobic and superoleophilic properties via a facile 1,4-conjugate addition reaction between amine and acrylate groups for coating nano-complex on the sponge surface and subsequently covalent modification with amine-functionalized long-chain alkane for decrease the surface energy. In order to satisfy the requirement of pore sizes in emulsion separation, a novel and controllable approach has been explored to control the pore sizes and 3D porous structure of the resultant sponge by the mechanical compression strategy. Notably, when the emulsified oil/water mixtures were poured into the modified sponge with 90% compression degree of its original volume, the demulsification occurred immediately and then the oil phase passed through the sponge quickly, while water droplets were interrupted in the tortuous pore channels. Combined with the special wettability and the novel pore sizes tuning strategy, the resulting sponges can effectively separate a wide range of surfactant-stabilized water-in-oil emulsions with fast permeation flux of 32,500 ± 2000 L m −2 h −1 bar −1 under the action of gravity and extremely high oil purity (>99.97%). It is expected that the superhydrophobic sponge with the novel compression approach can provide a general strategy for 3D porous materials used for effective separation of emulsified oil/water emulsions.
Facile fabrication of functional superhydrophobic porous materials with full biodegradability for efficient removal of oily pollutants from water has been of considerable interest for its great significance in environmental protection. Herein, a fully organic and biodegradable superhydrophobic sponge is fabricated with carnauba wax (CW) via dip-coating, nonsolvent induced phase separation and spraying processes on a freeze-dried pomelo peel. The as-fabricated sponge was covered with flower-shaped patterns aggregated by CW nanosheets, and presented great water repellency with a contact angle of 154°. Thanks to the 3D porous architecture and superhydrophobicity/superoleophilicity, the sponge exhibited great oil absorptive capacity, oil selectivity, separation efficiency and reusability for immiscible oil/water mixtures. Interestingly, the multi-layer compressed sponges realized gravity-driven surfactant-stabilized water-in-oil emulsion separation with high permeation flux of up to 5729 L·m −2 ·h −1 and excellent efficiency of oil purity larger than 99.9%. Importantly, the superhydrophobic sponge was derived from cheap renewable natural resources, and capable of being completely biodegraded after discarding. The findings conceivably stand out as a new tool to fabricate superhydrophobic materials with sustainability and biodegradability for oil accidents and industrial sewage emissions.
危险品化学品经营许可证（带存储）