Relationship between swelling and the electrohydrodynamic properties of functionalized carboxymethyldextran...

Area of Science:

• Polymer Science
• Physical Chemistry
• Materials Science

Background:

• Carboxymethyldextran (CMD) is a functionalized polysaccharide with significant applications.
• Understanding its behavior in solution is crucial for optimizing its use.
• Electrostatic and hydrodynamic properties are key to its functionality.

Purpose of the Study:

• To investigate the electrostatic, hydrodynamic, and swelling properties of CMD in aqueous solutions.
• To examine the impact of polycarboxylate charge and molar mass on CMD's electrohydrodynamic features.
• To analyze CMD's conformational transitions across a wide ionic strength range.

Main Methods:

• Combined protolytic titration, dynamic light scattering, and electrokinetic analyses were employed.
• Electrophoretic mobility and diffusion coefficients were measured.
• Soft-diffuse interface formalism was used for quantitative analysis.

Main Results:

• CMD exhibits soft particle behavior, with mobility increasing and swelling occurring as ionic strength decreases.
• Conformational transitions from compact random coil to swollen coil/wormlike structures were observed.
• Variations in size and mobility are dependent on CMD charge and molar mass, influencing chain stiffness and permeability.

Conclusions:

• CMD's electrohydrodynamic behavior is strongly influenced by its charge density and molar mass.
• Permeability and swelling are directly related to these properties, affecting chain conformation and density distribution.
• The study provides a quantitative understanding of CMD's behavior in solution, crucial for material design.