Date of Award
5-1-2026
Document Type
Dissertation
Degree Name
Ph.D. in Engineering Science
First Advisor
Dr. Sasan Nouranian
Second Advisor
Dr. Alexander M. Lopez
Third Advisor
Dr. Paul Scovazzo
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
The separation of carbon dioxide (CO2) from methane (CH4) is a critical process in natural gas upgrading and carbon management, yet conventional membrane materials suffer from inherent trade offs between selectivity and permeability. Ionic liquid (IL)-based membranes offer high CO2 affinity and tunable chemistry, but the mechanisms governing gas transport under nanoconfinement remain poorly understood, especially the roles of confinement geometry and interfacial ordering in controlling gas selectivity and permeability. This dissertation addresses this challenge through a multiscale computational investigation of nanoconfined ionic liquid membranes. Mesoscale simulations are used to determine how block copolymer composition and ionic liquid loading control self assembled morphology and confinement geometry, while atomistic molecular dynamics simulations quantify CO2/CH4 diffusivity, solubility, and selectivity under equilibrium and pressure driven conditions. Linking membrane morphology to molecular level transport establishes direct structure-transport relationships across length scales. The results show that nanoconfinement substantially alters ionic liquid structuring and dynamics relative to bulk behavior, giving rise to transport phenomena that cannot be predicted from bulk properties alone. Interfacial regions between polymers, ionic liquids, and confining surfaces dominate separation performance by preferentially stabilizing CO2, resulting in enhanced selectivity. Under pressure driven operation ionic liquid-gating is identified, in which ions dynamically accumulate at pore entrances and regulate gas access. These findings establish a molecular framework for understanding gas transport in ionic liquid membranes and guiding advanced membrane design.
Recommended Citation
Salmankhani, Azam, "Computational Investigation of Nanoconfinement Effects on Gas Separation in Copolymer/Ionic Liquid Membranes" (2026). Electronic Theses and Dissertations. 8871.
https://egrove.olemiss.edu/etd/8871