Controlling the Structure and Morphology of Organic Nanofilaments Using External Stimuli

Area of Science:

• Materials Science
• Organic Chemistry
• Nanotechnology

Background:

• Controlling the morphology of organic nanofilaments is crucial for advanced materials.
• Bent-core molecules offer unique self-assembly properties.
• External stimuli can induce phase transitions in molecular systems.

Purpose of the Study:

• To design and synthesize bent-core molecules capable of morphological changes.
• To investigate the response of these molecules to electric fields and UV light.
• To explore new methods for nanoscale structural control.

Main Methods:

• Synthesis of novel bent-core molecules with specific functional groups (chiral side chains, azobenzene).
• Characterization using differential scanning calorimetry, optical microscopy, CD spectropolarimetry, electron microscopy, UV-vis spectrophotometry, and X-ray diffraction.
• Analysis of phase behavior and nanoscale morphologies (helical nanofilaments, nanocylinders).

Main Results:

• Two distinct nanoscale morphologies, helical nanofilaments (HNFs) and layered nanocylinders, coexist in the absence of external stimuli.
• Application of an electric field induced a tilted smectic phase in chiral molecules, eliminating HNFs.
• UV irradiation led to the sole formation of HNFs in azobenzene-containing molecules, eliminating nanocylinders.

Conclusions:

• Bent-core molecules can be designed to undergo specific morphological transformations in response to external stimuli.
• Electric fields and UV light provide tunable control over nanoscale structures beyond cooling rates.
• This research expands the possibilities for manipulating the structure and morphology of bent-core molecule-based nanomaterials.