Wang Dong,Lin Junkang,Huang Jianhua,Zhang Hui,Lin Shan,Chen Lihui,Ni Yonghao,Huang Liulian
A major obstacle for the development of the cellulose-based nanofiltration membrane is its fouling. In this study, a novel cellulose-based composite nanofiltration membrane (CS/DA-TiO 2 -NFM) with excellent anti-fouling performance was prepared through casting of both chitosan (CS) and TiO 2 modified by dopamine (DA-TiO 2 ) on the cellulose substrate membrane. DA-TiO 2 was successfully introduced into the surface of membrane, resulting in significant improvement in its hydrophilicity due to the formation of dense CS layers. Furthermore, both CS and DA-TiO 2 were effective antimicrobial agents (against E. coli 90.6% and S. aureus 95.1%) that could minimize the accumulation of bacteria on the CS/DA-TiO 2 -NFM. For the antifouling test against BSA, the irreversible recovery ratio of the CS/DA-TiO 2 -NFM was only 23.25% of the control (no CS/DA-TiO 2 modified NFM). In addition, the CS/DA-TiO 2 -NFM exhibited an increased rejection rate of MgSO 4 (enhanced 40.93%) and water-flux (enhanced 18.10%) compared with the control. These results highlight the potential of the presented approach for designing membranes with effective separation performance and antifouling for drinking water treatment. Graphic abstract
Jin Wen,Xiaoke Li,He Zhang,Size Zheng,Caini Yi,Liu Yang,Jinwen Shi
Solar-powered water distillation is one of the effective and promising ways of water purification. However, new high-efficiency evaporators are especially needed to reduce the energy requirement and improve water yields under natural sunlight. In this study, a Janus structured hydrogel with an interpenetrating double network was formed by polyvinyl alcohol and natural polysaccharide to speed up solar water purification. Due to its unique pore structure, water molecules can quickly escape from the surface of Janus hydrogel by molecular dynamics simulations. The Janus evaporator worked stably and the evaporation rate was achieved to 3.53 kg·m −2 ·h −1 under 1 sun illumination, which was attributed to the outstanding water transport capacity and thermal localization capacity. Meanwhile, the Janus-based solar evaporator exhibited excellent durability in wide acid–base range (pH 1–13) and salinity range (0–350‰), and long term (30 days). The daily yield of the Janus hydrogel reached 24.5 kg·m −2 ·h −1 in outdoor tests. The Janus evaporator enables efficient desalination and purification of other unconventional water sources, and can degrade more than 95% of organic dyes (trypan blue and Congo red) as a result of the synergistic effect of Polydopamine (PDA) /TiO 2 nanoparticles. This Janus structured hydrogel evaporator opens up potential applications in desalination and wastewater treatment.
危险品化学品经营许可证（带存储）