Steric-Structure-Dependent Gel Formation, Hierarchical Structures, Rheological Behavior, and Surface Wettability.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Bicholesteryl-based molecules are explored for self-assembly.
• Controlling self-assembly is crucial for material properties.

Purpose of the Study:

• To design and synthesize bicholesteryl-based gelators with varying central linker atoms (C, N, O).
• To investigate how the central linker atom influences self-assembly behavior, morphology, and properties.
• To establish structure-property relationships for these novel gelators.

Main Methods:

• Gelation tests, field-emission scanning electron microscopy (FE-SEM), field-emission transmission electron microscopy (FE-TEM).
• UV/Vis absorption, IR spectroscopy, X-ray diffraction (XRD), rheology, and contact-angle measurements.
• Quantum-chemical calculations to analyze molecular structures.

Main Results:

• Gelation ability and morphology (nanofibers, nanosheets, nanospheres, nanotubes) depend on the central linker atom.
• GC and GN gel in three solvents; GO gels only in N,N-dimethylformamide (DMF).
• Gels exhibit varying tolerances to external forces; xerogels are hydrophobic (contact angles 121-152°).
• Quantum-chemical calculations reveal distinct steric structures for GC, GN, and GO.

Conclusions:

• The central linker atom is a key factor in modulating molecular steric structure.
• This modulation effectively controls supramolecular self-assembly processes and the resulting properties of gelators.
• The findings provide insights for designing tailored self-assembling materials.