Hydrophilic carbon nanotube membrane enhanced interfacial evaporation for desalination

• Published in: Chinese chemical letters 2022-04, Vol.33 (4), p.2155-2158
• Main Authors: Hou, Yaqi, Wang, Qianxiao, Wang, Shuli, Wang, Miao, Chen, Xuemei, Hou, Xu
• Format: Article
• Language: English
• Subjects: Carbon nanotube; Desalination; Hydrophilic surface chemistry; Molecular dynamic simulation; Water evaporation
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2021.09.007

Carbon nanotube-based (CNT-based) interfacial evaporation material is one of the most potential materials for solar desalination. Here, we studied the evaporation rate of the CNT-based membranes with different hydrophilic and hydrophobic chemical modified surfaces using molecular dynamic simulations. We found that the hydrogen bonding density among water molecules at the interface is a key factor in enhancing the evaporation rate. For a hydrophilic CNT-based membrane, the strong interactions between the membrane outer surface and the water molecules can destroy the water-water hydrogen bonding interactions at the interface, resulting in the reduction of the hydrogen bonding density, leading to an enhancement effect in evaporation rate. We also found that there is an optimal thickness for evaporation membrane. These findings could provide some theoretical guidance for designing and exploring advanced CNT-based systems with more beneficial performance in water desalination. The detailed microscopic mechanism behind the influence of the hydrophilic and hydrophobic surface chemistry of the interfacial evaporation membrane on the evaporation rate of solar desalination was studied using molecular dynamic simulations. The results show that the hydrophilic membrane material can significantly enhance the evaporation rate by destroying the hydrogen bonding interactions among water molecules at the interface. [Display omitted]