Undulating Cylinder-in-Lamellae Morphologies Formed in Giant Bolaform Lipids

Area of Science:

• Materials Science
• Polymer Chemistry
• Supramolecular Chemistry

Background:

• Unconventional material phases are often derived from complex molecular architectures.
• Giant bolaform lipids offer a versatile platform for exploring novel self-assembled structures.

Purpose of the Study:

• To synthesize and characterize novel giant bolaform lipids with polyhedral oligomeric silsesquioxane (POSS) moieties.
• To investigate the phase behavior and self-assembly of these lipids by varying the POSS volume fraction.
• To elucidate the formation mechanism of unconventional phases through structural analysis.

Main Methods:

• Facile synthesis of giant bolaform lipids incorporating oligosiloxane-functionalized POSS and perfluoroalkyl-functionalized POSS (FPOSS).
• Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) for phase identification and structural analysis.
• Temperature-dependent experiments and structural parameter calculations to understand phase formation.

Main Results:

• Successful synthesis of giant bolaform lipids with tunable Si_x POSS content.
• Identification of various self-assembled phases, including lamellae (LAM), three-phase-four-layer lamellae (LAM3), and a unique column in undulating lamellae (Col_c2-in-LAMu) phase.
• Observation of lamellar layers oriented parallel to the substrate in thin films.

Conclusions:

• Molecular topology engineering of giant bolaform lipids enables the formation of diverse and unconventional supramolecular phases.
• The study provides insights into controlling macromolecular assembly and understanding phase formation mechanisms.
• This research contributes to the design principles for advanced functional materials based on complex molecular architectures.