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Published on: December 20, 2013
Single molecular pair interactions between hydrophobically modified hydroxyethyl cellulose and amylose determined by
Makoto Takemasa1, Marit Sletmoen, Bjørn T Stokke
1Biophysics and Medical Technology, Department of Physics, The Norwegian University of Science and Technology, NTNU, NO-7491 Trondheim, Norway.
Langmuir : the ACS Journal of Surfaces and Colloids
|June 6, 2009
Summary
Single molecule force spectroscopy revealed hydrophobic interactions in hydrophobically modified hydroxyethyl cellulose (HMHEC) and between HMHEC and amylose. These interactions influence the macroscopic properties of polysaccharide solutions.
Area of Science:
- Polymer Science
- Biophysical Chemistry
- Materials Science
Background:
- Hydrophobically modified hydroxyethyl cellulose (HMHEC) is a polymer used in various applications.
- Understanding polymer interactions at a molecular level is crucial for predicting macroscopic properties.
- Amylose, a component of starch, can interact with other polymers.
Purpose of the Study:
- To investigate the single molecular interactions between HMHEC and between HMHEC and amylose.
- To quantify the forces involved in these interactions using dynamic force spectroscopy.
- To correlate molecular interactions with the associative behavior of polysaccharide solutions.
Main Methods:
- Dynamic force spectroscopy (DFS) using a scanning probe-based platform.
- Investigation of single molecular pair interactions in aqueous solutions.
- Analysis of rupture force distribution using the Bell-Evans model.
Main Results:
- Both HMHEC-HMHEC and HMHEC-amylose interactions exhibited stretching-type peaks, indicating hydrophobic association.
- Most probable rupture forces ranged from 27-125 pN for HMHEC-HMHEC and 13-34 pN for HMHEC-amylose, depending on force loading rates.
- Energy barrier distance and apparent lifetime were dependent on force loading rates, with distinct values for HMHEC-HMHEC and HMHEC-amylose interactions.
Conclusions:
- The study quantifies the hydrophobic interactions governing HMHEC self-association and its association with amylose.
- The findings provide a molecular basis for the observed macroscopic properties of aqueous HMHEC and amylose solutions.
- Dynamic force spectroscopy is effective in elucidating the mechanics of polysaccharide interactions.
