Thermo-Responsive Cellulose-Based Material with Switchable Wettability for Controllable Oil/Water Separation

• Published in: Polymers Vol. 10; no. 6; p. 592
• Main Authors: Chen, Wenbo, He, Hui, Zhu, Hongxiang, Cheng, Meixiao, Li, Yunhua, Wang, Shuangfei
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 28.05.2018; MDPI AG
• Subjects: cellulose; chemical grafting; controllable oil/water separation; in situ variable-temperature NMR; thermo-responsive; thermo-responsive; chemical grafting; controllable oil/water separation; in situ variable-temperature NMR; cellulose
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym10060592

A thermo-responsive cellulose-based material (cellulose- -PNIPAAm) was prepared by grafting -isopropylacrylamide (NIPAAm) onto bagasse pulp cellulose via Ce (IV)-initiated free radical polymerization. The surfaces of the obtained cellulose- -PNIPAAm paper showed a rapid wettability conversion from being hydrophilic (water contact angles (WCA) of 0°) at 25 °C to becoming hydrophobic (WCA of 134.2°) at 45 °C. Furthermore, the thermo-responsive mechanism of cellulose- -PNIPAAm was examined by the in situ variable-temperature C NMR, ¹H NMR and AFM analysis. At the same time, the resulting cellulose paper was applied for a switchable separation of oil/water mixtures. Water can pass through the paper under 45 °C, while oil is kept on the paper. When the temperature is above 45 °C, oil can permeate through the paper, while water cannot pass through the water. Moreover, the paper exhibited excellent regeneration performance after five cycles and maintained its switchable wettability.