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Gas Permeability of Hyperthin Polyelectrolyte Multilayers Having Matched and Mismatched Repeat Units.
Song Yi1, Cen Lin1, William Leon1
1Department of Chemistry, Lehigh University , Bethlehem, Pennsylvania 18015, United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|April 8, 2016
Summary
Polyelectrolyte multilayer (PEM) permeability is not dictated by polyelectrolyte matching. Instead, higher concentrations of pendant aryl groups increase permeability and membrane compliance.
Area of Science:
- Materials Science
- Polymer Chemistry
- Membrane Science
Background:
- Polyelectrolyte multilayers (PEMs) are versatile materials with tunable properties.
- Understanding factors influencing PEM permeability is crucial for applications like filtration and drug delivery.
Purpose of the Study:
- To investigate the impact of polyelectrolyte structural similarity on the permeability of hyperthin PEMs.
- To identify key chemical features governing PEM permeability.
Main Methods:
- Fabrication of PEMs using matched, semimatched, and mismatched polyelectrolyte pairs.
- Measurement of nitrogen (N2) gas permeance through the PEMs.
- Atomic Force Microscopy (AFM) indentation to assess mechanical properties.
Main Results:
- Polyelectrolyte matching did not significantly influence membrane permeability.
- PEM permeability varied by a factor of 20, strongly correlating with pendant aryl group concentration.
- Higher permeability PEMs exhibited greater compliance, as indicated by AFM indentation.
Conclusions:
- The concentration of pendant aryl groups, not polyelectrolyte similarity, is a primary determinant of PEM permeability.
- PEM compliance is linked to permeability, suggesting a structure-property relationship.
- A wide range of polyelectrolyte combinations should be explored for optimizing PEM functional properties.
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