Li Yinchun, Gong Depeng, Zhou Youliang, Zhang Chaocan, Zhang Chunyang, Sheng Yitian, Peng Shu
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Polymers (Basel). 2022 Apr 14;14(8):1596. doi: 10.3390/polym14081596.
Organogel adsorbents are widely used for the adsorption of hard-to-degrade organic pollutants in wastewater due to their natural affinity to the organic phase in water. In this study, phenolic xerogels (PF) synthesised in the ethylene glycol inorganic acid system are used as a backbone and superhydrophobic phenolic xerogels (ASO-PF) are obtained by grafting aminosilanes onto the PF backbone via the Mannich reaction. The modified ASO-PF not only retains the pore structure of the original PF (up to 90% porosity), but also has excellent superhydrophobic properties (water contact angle up to 153°). Owing to the unique pore structure, ASO-PF has excellent compression properties, cycling 50% compression deformation more than 10 times without being damaged, with a maximum compression deformation of up to 80%. A squeeze-suction-squeeze approach is proposed for selective adsorption of organic pollutants in homogeneous solutions based on the recyclable compression properties of ASO-PF. The ASO-PF is put under negative pressure by squeezing, and when the pressure is released, the adsorbed liquid enters the ASO-PF, where the organic pollutants are retained by the adsorption sites in the skeleton, and then the remaining water is discharged by squeezing. This breathing ASO-PF holds great promise for organic pollutant adsorption and recovery applications.
有机凝胶吸附剂因其对水中有机相的天然亲和力而被广泛用于吸附废水中难降解的有机污染物。在本研究中，以在乙二醇无机酸体系中合成的酚醛干凝胶（PF）为骨架，通过曼尼希反应将氨基硅烷接枝到PF骨架上，得到超疏水酚醛干凝胶（ASO-PF）。改性后的ASO-PF不仅保留了原始PF的孔结构（孔隙率高达90%），还具有优异的超疏水性能（水接触角高达153°）。由于其独特的孔结构，ASO-PF具有优异的压缩性能，能承受50%的压缩变形超过10次而不损坏，最大压缩变形可达80%。基于ASO-PF可回收的压缩性能，提出了一种挤压-抽吸-挤压方法用于选择性吸附均相溶液中的有机污染物。通过挤压使ASO-PF处于负压状态，当压力释放时，被吸附的液体进入ASO-PF，其中有机污染物被骨架中的吸附位点保留，然后通过挤压排出剩余的水。这种具有呼吸功能的ASO-PF在有机污染物吸附和回收应用方面具有巨大潜力。
