• 文献标题:   Molecular Simulations on Tuning the Interlayer Spacing of Graphene Nanoslits for C4H6/C4H10 Separation
  • 文献类型:   Article
  • 作  者:   XU YX, HU ZF, LIU ZB, ZHU HJ, YAN YS, XU JB, YANG C
  • 作者关键词:   c4h6/c4h10 separation, interlayer spacing, graphene slit, adsorption, diffusion, molecular dynamics simulation
  • 出版物名称:   ACS APPLIED NANO MATERIALS
  • ISSN:  
  • 通讯作者地址:  
  • 被引频次:   2
  • DOI:   10.1021/acsanm.0c03336 EA FEB 2021
  • 出版年:   2021

▎ 摘  要

There are great challenges in developing efficient membranes to replace the currently energy-intensive cryogenic distillation processes for purifying C4H6 from C4H6/C4H10 mixtures due to their similar physical and chemical properties. Here, we investigated the performance of graphene slits with different interlayer spacings for C4H6/C4H10 separation via molecular simulations. The results demonstrate that the 3.4-angstrom-interlayer-spacing graphene slit only allows the penetration of C4H6 due to the size sieving effect and the permeance of C4H6 is up to 2.09 x 10(6) GPU. When the interlayer spacing increases to 3.6-6.8 angstrom, the graphene slits still exhibit the preferential penetration for C4H6 over C4H10 due to the pi-pi adsorption interaction between graphene sheets and C4H6. Surprisingly, the graphene slits (>10.2 angstrom) exhibit the preferential penetration for C4H10 over C4H6 owing to the diffusivity of C4H10 being much larger than that of C4H6 under confined conditions. In conclusion, by fine-tuning the interlayer spacing of graphene slits, the dominant separation mechanism is switched in the order of size sieving, thermodynamic adsorption, and dynamic diffusion, thereby achieving the controllable regulation of the preferential permeation from C4H6 to C4H10. C4H10 -selective membranes are of great significance for energy saving. The tuning strategy is expected to be applied in different paraffin/olefin separation scenarios such as high-content and low-content olefin feedstocks.