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Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
Intermolecular interactions as controlling factor for water sorption into polymer membranes
A Gugliuzza1, G De Luca, E Tocci
1Research Institute on Membrane Technology (ITM-CNR), Via Pietro Bucci, Cubo 17/C, I-87030 Rende (CS), Italy. a.gugliuzza@itm.cnr.it
The Journal of Physical Chemistry. B
|July 5, 2007
Summary
Modified poly(ether amide) (PEBAX) membranes with aromatic sulfonamide (KET) showed increased water sorption due to altered polar group availability. KET-KET dimer formation reduced water-modifier interactions, impacting membrane polarization.
Area of Science:
- Polymer Science
- Materials Science
- Physical Chemistry
Background:
- Block co-poly(ether amide) (PEBAX) membranes are utilized in various applications, but their water sorption properties require detailed understanding.
- Modifying PEBAX with additives can alter its physicochemical characteristics, including water uptake.
- Controlling water sorption is crucial for membrane performance in humid environments.
Purpose of the Study:
- To elucidate the mechanisms governing water sorption in modified PEBAX membranes.
- To investigate the effect of aromatic sulfonamide (KET) incorporation on PEBAX membrane properties.
- To correlate molecular interactions with macroscopic water sorption behavior.
Main Methods:
- Multidisciplinary approach combining experimental and theoretical techniques.
- Infrared (IR) spectroscopy to analyze polar group availability and hydrogen bonding.
- Molecular dynamics (MD) and quantum chemical (QC) calculations for molecular-level insights.
- Surface energy measurements to assess changes due to modification.
Main Results:
- Nonlinear increase in water sorption with increasing KET concentration.
- Nonlinear changes in membrane surface energies observed.
- IR analysis indicated altered accessibility of polar groups and hydrogen bonding.
- MD/QC simulations revealed KET-KET dimer formation reduces water-modifier interaction energy.
- Water-dimer complex formation at higher KET concentrations decreased dipole moments, hindering polymer chain polarization.
Conclusions:
- KET incorporation significantly influences water sorption in PEBAX membranes.
- The formation of KET-KET dimers is a key factor in modulating water-polymer interactions.
- Altered polarity and reduced polymer chain polarization contribute to the observed water sorption behavior.
- This study provides a molecular-level understanding of water sorption in modified PEBAX membranes.
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