Surface activity and emulsification properties of hydrophobically modified dextrans

Area of Science:

• Polymer Chemistry
• Surface Science
• Colloid Science

Background:

• Polysaccharides like dextran can be modified to create novel functional materials.
• Polymeric surfactants offer tunable properties for various applications.
• Understanding polymer adsorption at interfaces is crucial for stabilization.

Purpose of the Study:

• To synthesize and characterize neutral polymeric surfactants based on dextran.
• To investigate the relationship between hydrophobic substitution and associative/surface-active properties.
• To evaluate the performance of these surfactants in emulsion stabilization, emulsion polymerization, and protein adsorption prevention.

Main Methods:

• Covalent attachment of hydrophobic groups to a dextran backbone.
• Viscometric measurements to assess associative behavior.
• Surface and interfacial tension measurements to determine surface activity.
• Dynamic light scattering and zeta potential measurements for emulsion characterization.
• Emulsion polymerization of styrene and colloidal stability assessment.

Main Results:

• Synthesized dextran derivatives showed tunable associative behavior and surface activity, increasing with hydrophobic substitution.
• The polymers formed dense layers at interfaces, stabilizing dodecane-in-water emulsions.
• Stable polystyrene particles with adsorbed dextran layers were produced via emulsion polymerization.
• The modified dextrans provided colloidal stability and protected particles from protein adsorption.

Conclusions:

• Dextran-based polymeric surfactants are effective stabilizers for emulsions and particles.
• Hydrophobic modification of polysaccharides offers a versatile route to advanced materials.
• These surfactants demonstrate potential in preventing protein fouling and enhancing colloidal stability.