Nanopipet and truncated cone pores; influence of the cone size and density on fluid structure and adsorption: DFT approach

• Published in: Journal of molecular liquids 2019-03, Vol.277, p.856-864
• Main Authors: Rabiei Dehnavi, Razieh, Keshavarzi, Ezat
• Format: Article
• Language: English
• Subjects: Confined fluid; Density functional theory; Nanopores with cone geometries; Surface adsorption; Truncated cone
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2019.01.007

The modified fundamental measure theory, MFMT is employed to investigate the hard sphere structure inside and around nanopipet pores. Our findings show that fluid molecules have a strong tendency to accumulate at the conical part of the nanopipet. This allows the fluid to have a greater layering in its structure in the cone region in comparison to the cylindrical part. For the cone region, contact density at the concave wall decreases with the radius of the cross section. Also, a pronounced maximum peak observed for contact density of fluids in the pore in the junction of the two parts of a nanopipet. A reverse behavior is, however, observed for fluid density at the convex outer wall. Comparison of fluid adsorption in nano-cylindrical with nanotruncated cone pores of identical volumes reveals that the first kind of pore record higher adsorption values for reduced integer values of tip radius. [Display omitted] •We investigated the tendency of molecules to adsorb in nanopipet and truncated cone pores via MFMT.•Results show a maximum contact density at junction of conical and cylindrical part of a nanopipet.•Fluid adsorption in truncated cone has been compared with nanocylindrical pores at the same volume.•Results reveals predominance of nanotruncated cone for its integer tip's radius.•Contact density at the wall of nanopipet decreases with radius of its cross section.