Viscoelastic lyotropic liquid crystals formed in a bio-based trimeric surfactant system

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Colloid and Surface Chemistry

Background:

• Oligomeric surfactants bridge the gap between conventional and polymeric surfactants.
• Bio-based surfactants offer sustainable alternatives in materials science.
• Rosin, a natural resource, can be utilized for synthesizing novel surfactant structures.

Purpose of the Study:

• To synthesize a novel bio-based star-shaped trimeric quaternary ammonium surfactant from rosin.
• To investigate the self-assembly behavior of this trimeric surfactant in aqueous systems.
• To explore the formation and properties of lyotropic liquid crystals (LLCs) using this surfactant.

Main Methods:

• Synthesis of a bio-based trimeric quaternary ammonium surfactant (tri-R-4-Phe) from rosin.
• Formation of tertiary systems with C12EO3 and water.
• Characterization using polarizing optical microscopy (POM), small-angle X-ray scattering (SAXS), and rheological measurements.

Main Results:

• The synthesized tri-R-4-Phe surfactant exhibits strong affinity for both water and organic compounds.
• The tri-R-4-Phe/C12EO3/water system forms lamellar lyotropic liquid crystals over a wide concentration range.
• Samples displayed significant viscoelasticity, increasing with surfactant concentration, and exhibited shear banding phenomena due to shear-induced phase transitions.

Conclusions:

• The study reveals the unique behavior of trimeric surfactants in lyotropic liquid crystal systems.
• The findings contribute to understanding delicate molecular self-assembly processes.
• Utilizing natural resources like rosin for advanced materials development is demonstrated.