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Updated: Jul 11, 2026
10:53
Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
Kinetics of pH response for copolymer films with dilute carboxylate functionality
Dongshun Bai1, Craig L Hardwick, Brad J Berron
1Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA.
The Journal of Physical Chemistry. B
|September 11, 2007
Summary
We studied how polymer film properties affect pH response. Thinner films and higher acid content accelerate pH-induced protonation and ionization, crucial for responsive materials.
Area of Science:
- Polymer Science
- Electrochemistry
- Materials Science
Background:
- Responsive polymer films are crucial for various sensing applications.
- Understanding film composition and thickness effects on response rate is key.
Purpose of the Study:
- To investigate how film composition and thickness influence the pH-induced response rate of polymethylene-based copolymer films.
- To correlate electrochemical impedance changes with pH variations.
Main Methods:
- Surface-catalyzed polymerization and hydrolysis to prepare copolymer films (PM-CO2H) on gold electrodes.
- Electrochemical impedance spectroscopy at 100 Hz to monitor film barrier properties during pH changes.
- Systematic variation of film acid content and thickness.
Main Results:
- Copolymer films with 1-3% molar acid content showed a 2-order magnitude impedance change with pH shifts (11 to 4 or 4 to 11).
- Protonation rates were slower than ionization rates due to film hydrophobicity.
- Increased acid content and reduced film thickness (50 nm) accelerated both protonation and ionization rates.
Conclusions:
- Film composition and thickness significantly impact the rate of pH-induced response.
- Optimized film properties can enhance the speed of protonation and ionization for responsive materials.
- These findings are vital for designing advanced pH-sensitive polymer systems.
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