Preparation and characterization of a novel fluorine-free and pH-sensitive hydrophobic porous diatomite ceramic as highly efficient sorbent for oil–water separation

• Published in: Separation and purification technology Vol. 254; p. 117620
• Main Authors: Han, Lei, Wu, Wenhao, Huang, Zhong, Lei, Wen, Li, Saisai, Zhang, Haijun, jia, Quanli, Zhang, Shaowei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2021
• Subjects: Fluorine-free; Hydrophobicity; ISOBAM-104; Oil/water separation; pH-sensitive; Porous diatomite ceramic; pH-sensitive; Fluorine-free; Oil/water separation; Hydrophobicity; Porous diatomite ceramic; ISOBAM-104
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2020.117620

[Display omitted] •Fluorine-free ISOBAM-104 as a modifying agent to prepare hydrophobic porous sample.•The sample exhibited hydrophobic in strong acid whereas hydrophilic in strong alkali.•The sample performed excellent adsorption ability and reliability recyclability. The development of sorbents with hydrophobicity or hydrophilicity is key in tackling increasingly serious oil spill/leakage problems. In this work, fluorine-free and pH-sensitive hydrophobic porous diatomite ceramics modified by isobutylene-maleic anhydride copolymer were successfully synthesized for the first time, via a simple but novel impregnation and heat-treatment method. Upon the removal of hydroxyl groups via 1 h heating at 573 K in a 5% H2/Ar atmosphere, the amide groups in the original isobutylene-maleic anhydride copolymer were transformed to imide groups, conferring excellent hydrophobicity and oil/water separation capacity on the final porous ceramics. As-prepared hydrophobic porous diatomite ceramics were pH-sensitive and exhibited hydrophobic behavior in strong acid (pH = 1) whereas hydrophilic behavior in strong alkali (pH = 13). Their adsorption capacity for oil/water separation was 1.7–60 times as high as that of their conventional inorganic sorbent counterparts.