Tailoring Interfacial Activity of pH-Driven Shellac-Chitosan Nanocomposites via Solution Addition Sequence for...

Area of Science:

• Materials Science
• Colloid and Surface Chemistry

Background:

• Shellac (SH) and chitosan (CS) are natural polymers with potential for forming interfacial nanocomposites.
• The influence of solution addition sequence on SH-CS nanocomposite formation and properties is not well understood.

Purpose of the Study:

• To investigate how the addition order of SH and CS solutions affects the formation, physicochemical properties, and interfacial activity of SH-CS nanocomposites.
• To elucidate the role of pH, electrostatic interactions, and other forces in the assembly process.

Main Methods:

• Systematic investigation of SH-CS mixing with varying addition sequences.
• Characterization of nanocomposite formation and properties using techniques like FTIR.
• Evaluation of interfacial activity and emulsifying performance.

Main Results:

• pH variation during mixing drives nanocomposite formation, with optimal interactions near pH 5.0.
• The SH:CS mass ratio of 2:3 yielded the most efficient assembly.
• Addition sequence dictated structure: SH to CS produced core-shell, while CS to SH yielded co-assembled hybrids.
• Co-assembled nanocomposites showed balanced wettability, reduced interfacial tension, and enhanced emulsifying performance.

Conclusions:

• The addition sequence is a critical factor in tailoring the structure and properties of pH-driven SH-CS nanocomposites.
• Co-assembled SH-CS nanocomposites demonstrate significant potential as high-performance Pickering emulsifiers.