Interactions between cellulose nanocrystals and conventional/gemini surfactants.

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Nanotechnology

Background:

• Research on surfactant-cellulose nanocrystal (CNC) interactions primarily involves conventional surfactants.
• Interactions between CNC and gemini surfactants remain largely unexplored.

Purpose of the Study:

• To investigate and characterize the interactions between CNC and both conventional (tetradecyltrimethylammonium bromide, TTAB) and gemini surfactants (asymmetric 14-6-6 and symmetric 14-6-14).
• To elucidate the binding mechanisms and identify distinct interaction regimes for gemini surfactants with CNC.

Main Methods:

• Comparative analysis of surfactant-CNC interactions using varying surfactant concentrations.
• Observation of adsorption, micellization, and dilution phenomena.
• Assessment of pH and electrolyte effects on binding behavior.

Main Results:

• Conventional surfactant (TTAB)/CNC interactions showed three regions: electrostatic interaction, CNC-induced micellization, and micelle dilution.
• Gemini surfactant/CNC interactions exhibited four regimes: cooperative adsorption, CNC-induced micellization, micelle formation, and dilution.
• CNC influenced gemini surfactant partitioning to the air-water interface differently at low and high concentrations.
• pH minimally impacted low CNC concentration binding, but significantly affected higher concentrations.
• Electrolytes reduced electrostatic interactions, influencing CNC-induced micellization.

Conclusions:

• Gemini surfactants display unique interaction patterns with CNC compared to conventional surfactants.
• CNC plays a crucial role in promoting or inhibiting gemini surfactant micellization and interfacial partitioning.
• Environmental factors like pH and electrolytes modulate the complex interplay between CNC and gemini surfactants.