title: Thermodynamics and Kinetics of Gas Storage in Porous Liquids.
abstract: The recent synthesis of organic molecular liquids with permanent porosity opens up exciting new avenues for gas capture, storage, and separation. Using molecular simulations, we study the thermodynamics and kinetics for the storage of CH4, CO2, and N2 molecules in porous liquids consisting of crown-ether-substituted cage molecules in a 15-crown-5 solvent. It is found that the intrinsic gas storage capacity per cage molecule follows the order CH4 > CO2 > N2, which does not correlate simply with the size of gas molecules. Different gas molecules are stored inside the cage differently; e.g., CO2 molecules prefer the cage's core whereas CH4 molecules favor both the core and the branch regions. All gas molecules considered can enter the cage essentially without energy barriers and leave the cage on a nanosecond time scale by overcoming a modest energy penalty. The molecular mechanisms of these observations are clarified.
authors.affiliation: Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Fengchang
authors.initials: F
authors.lastname: Yang
authors.affiliation: Center for Nanophase Materials Sciences and Computer Science & Mathematics Division, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
authors.forename: Jingsong
authors.initials: J
authors.lastname: Huang
authors.affiliation: Center for Nanophase Materials Sciences and Computer Science & Mathematics Division, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
authors.forename: Bobby G
authors.initials: BG
authors.lastname: Sumpter
authors.affiliation: Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Rui
authors.initials: R
authors.lastname: Qiao