Molecular insights into the microstructure of ethanol/water binary mixtures confined within typical 2D nanoslits

The role of the adsorbed layers induced by different solid surfaces

Document identifier: oai:DiVA.org:ltu-77920
Access full text here:10.1016/j.fluid.2019.112452
Keyword: Engineering and Technology, Mechanical Engineering, Energy Engineering, Teknik och teknologier, Maskinteknik, Energiteknik, Two-dimensional materials, Aqueous ethanol solutions, Molecular simulations, Diffusion, Nanoconfinement
Publication year: 2020
Relevant Sustainable Development Goals (SDGs):
SDG 11 Sustainable cities and communitiesSDG 6 Clean water and sanitationSDG 2 Zero hunger
The SDG label(s) above have been assigned by OSDG.ai

Abstract:

With the emergence of membrane separation and heterogeneous catalysis applications that are associated with confined ethanol/water binary mixture in the pores of two-dimensional (2D) nanomaterials, understanding their confined microstructures is the first step for further relevant applications. In this work, molecular dynamics was performed to investigate the microstructure of ethanol/water binary mixture of 5% mole fraction confined within the four typical 2-nm width 2D-nanoslits (i.e. hBN, GO-0.2, GO-0.4 and Ti3C2(OH)2). Results demonstrated that different chemical properties of solid surfaces can induce distinctive microstructures of mixed fluid within the interfacial contact (adsorbed) layer and thus can result in different mobility of water molecules within the subcontact layer. The residence times of water molecules in the subcontact layer were found in the sequence of Ti3C2(OH)2 > hBN > GO-0.4 > GO-0.2, whereas their sequence of diffusion coefficient within the x-z plane was Ti3C2(OH)2 > hBN > GO-0.2 > GO-0.4. Detailed hydrogen bond (HB) microstructure analysis showed that a high average number of HBs (between fluid molecules of the interfacial contact layer and water molecules of the subcontact layer) induced by solid surfaces could facilitate water molecules to reside in the subcontact layer. Moreover, the small average number of HBs between the water molecules themselves in the subcontact layer could lead to high in-plane diffusion coefficients.

Authors

Yao Qin

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Nana Zhao

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Yudan Zhu

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Yumeng Zhang

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Qingwei Gao

Luleå tekniska universitet; Energivetenskap; College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Zhongyang Dai

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Yajing You

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Xiaohua Lu

College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University
Other publications >>

Record metadata

Click to view metadata