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Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Anions as efficient chain stoppers for hydrogen-bonded supramolecular polymers
Thomas Pinault1, Caroline Cannizzo, Bruno Andrioletti
1UPMC Univ Paris 06, UMR 7610, Chimie des Polymères, F-75005 Paris, France.
Langmuir : the ACS Journal of Surfaces and Colloids
|March 17, 2009
Summary
Simple anions effectively control supramolecular polymer chain length and viscosity. This discovery offers a straightforward method for tuning rheological properties in hydrogen-bonded polymers, impacting material science applications.
Area of Science:
- Supramolecular Chemistry
- Polymer Science
- Rheology
Background:
- Hydrogen-bonded supramolecular polymers' properties depend on chain length.
- Chain length is typically controlled using specific monofunctional monomers (chain stoppers).
- Tuning rheology is crucial for material applications.
Purpose of the Study:
- To investigate anions as simple, effective chain stoppers for bisurea-based supramolecular polymers.
- To evaluate the efficiency of anions in controlling polymer chain length and rheological properties.
- To compare anion stoppers with previously developed organic stoppers.
Main Methods:
- Utilizing anions as hydrogen bond competitors to disrupt polymer chains.
- Characterizing rheological properties (viscosity) of bisurea solutions with varying anion concentrations.
- Analyzing the impact of anions on supramolecular assembly structure.
Main Results:
- All tested anions successfully broke supramolecular chains, significantly reducing solution viscosity.
- Anions proved more efficient than previously described organic stoppers.
- Even at a low molar fraction (10^-5), anions decreased viscosity by a factor of 10.
- The presence of specific anions (e.g., H2PO4, N(C4H9)4) did not alter the fundamental nature of the bisurea assembly.
Conclusions:
- Anions serve as a simple and highly effective method for controlling the rheology of hydrogen-bonded supramolecular polymers.
- This approach offers a significant advancement over traditional chain stoppers, simplifying polymer modification.
- The findings open new avenues for designing and manipulating materials with tailored flow properties.
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