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Summary
Polymer membranes and sorbents are critical technologies for addressing challenges in water purification, carbon capture, and energy storage. These materials control the selective transport of water, ions, and small molecules through complex polymer networks.
Our work focuses on developing advanced measurement methods that quantify how polymer structure and dynamics govern transport and selectivity. By establishing rigorous structure–property–performance relationships, we enable the design of next-generation membrane materials for the energy–water nexus.
Description
In Situ Sorption Measurements
We develop and apply coupled techniques to probe chemical interactions during membrane operation:
- Quartz Crystal Microbalance (QCM) for mass uptake
- Polarization Modulation Infrared Reflection Absorption Spectroscopy (PM-IRRAS) for chemical speciation
- In-situ Spectroscopic Ellipsometry (SE) for thickness change
- Inverse gas chromatography (IGC) for surface energy and solubility parameters
These methods enable real-time observation of gas and vapor sorption, including CO₂ and water, within thin polymer films.
Objective: Understand swelling, sorption, and chemical interactions under realistic conditions.
NMR Characterization of Polymer Networks
Solid-state NMR provides detailed insight into disordered polymer structures:
- Quantification of chemical composition and crosslinking
- Analysis of spatial proximity between functional groups
- Measurement of water diffusion via pulsed field gradient NMR
These approaches are essential for resolving the structure of highly crosslinked polyamide membranes.
Objective: Build atomistic understanding of membrane chemistry and transport.
Model Membranes & Controlled Architectures
We develop model systems of highly crosslinked polyamide membranes with precise control over structure to enable fundamental studies:
- Layer-by-layer fabricated polyamide membranes
- Tunable thickness, roughness, and surface chemistry
- Reduced heterogeneity compared to conventional interfacial polymerization
These systems enable systematic investigation of how individual variables affect performance of highly crosslinked polyamide membranes
Objective: Provide reference materials for validating measurement techniques and theories.
Why It Matters
A major challenge in membrane science is the lack of quantitative understanding linking molecular structure to transport performance.
Our work addresses this gap by delivering:
- Standardized, reproducible measurement methods
- Fundamental insights into polymer behavior
- Data that supports predictive modeling and materials design