Anomalous Depletion of Pore-Confined Carbon Dioxide upon Cooling below the Bulk Triple Point: An In Situ Neutron Diffraction Study

The phase behavior of sorbed CO{2} in an ordered mesoporous silica sample (SBA-15) was studied by neutron diffraction. Surprisingly, upon cooling our sample below the bulk critical point, confined CO{2} molecules neither freeze nor remain liquid as expected, but escape from the pores. The phenomenon...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2016-01, Vol.116 (2), p.025502-025502, Article 025502
Main Authors: Stefanopoulos, K L, Katsaros, F K, Steriotis, Th A, Sapalidis, A A, Thommes, M, Bowron, D T, Youngs, T G A
Format: Article
Language:English
Subjects:
Carbon dioxide
Cooling
Depletion
Fluid dynamics
Liquids
Molecular sieves
Neutron diffraction
Porosity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The phase behavior of sorbed CO{2} in an ordered mesoporous silica sample (SBA-15) was studied by neutron diffraction. Surprisingly, upon cooling our sample below the bulk critical point, confined CO{2} molecules neither freeze nor remain liquid as expected, but escape from the pores. The phenomenon has additionally been confirmed gravimetrically. The process is reversible and during heating CO{2} refills the pores, albeit with hysteresis. This depletion was for the first time observed in an ordered mesoporous molecular sieve and provides new insight on the phase behavior of nanoconfined fluids.
ISSN:0031-9007
1079-7114
DOI:10.1103/PhysRevLett.116.025502