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Updated: Jan 7, 2026
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Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems
Published on: April 28, 2016
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Phase transition dynamics of HBDBA-MWCNT nanocomposites probed by temperature-dependent Raman spectroscopy
Ummer Bashir Khoja1, Chandan Bhai Patel2, Sachin K Singh3
1Department of Allied Sciences (Physics), Graphic Era (Deemed to be University), Dehradun 248002, U.K., India.
Summary
This study shows how multi-walled carbon nanotubes (MWCNTs) affect the phase transitions of a liquid crystal (HBDBA). Adding MWCNTs changes the material's interactions and transition temperatures, offering insights into advanced material properties.
Area of Science:
- Materials Science
- Nanotechnology
- Physical Chemistry
Background:
- Liquid crystals (LCs) exhibit unique phase behaviors crucial for display technologies.
- Nanocomposites offer tunable properties by integrating nanomaterials into LC matrices.
- Understanding molecular interactions in LC-nanomaterial systems is key to developing novel functional materials.
Purpose of the Study:
- To investigate the influence of multi-walled carbon nanotubes (MWCNTs) on the phase transition behavior of a specific liquid crystalline system, N-(o-hydroxybenzylidene)-N'-(4-n-alkoxybenzylidene) (HBDBA).
- To analyze the dispersion and interaction dynamics of MWCNTs within the HBDBA matrix at varying temperatures.
- To elucidate the impact of MWCNTs on the intermolecular and intramolecular interactions governing the phase transitions of HBDBA.
Main Methods:
- Polarizing optical microscopy (POM) for observing MWCNT dispersion and liquid crystal behavior.
- Temperature-dependent Raman spectroscopy to monitor changes in HBDBA's molecular vibrations upon MWCNT incorporation.
- Density Functional Theory (DFT) calculations, including potential energy distribution (PED), to support experimental vibrational mode analysis.
Main Results:
- Distinct Raman spectral signatures were observed for the HBDBA-MWCNT composite compared to pristine HBDBA.
- Analysis of Raman bands associated with linking groups (NN, CN) and phenyl rings revealed altered intermolecular and intramolecular dynamics with temperature.
- MWCNTs were found to modify the intermolecular interaction network of HBDBA, influencing phase transition dynamics and temperatures.
Conclusions:
- Incorporation of functionalized MWCNTs significantly alters the phase transition behavior of the HBDBA liquid crystal.
- MWCNTs act as modulators of intermolecular forces within the liquid crystalline matrix.
- This research provides a foundation for designing tailored liquid crystalline nanocomposites with controlled phase transition properties.
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