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Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks MOFs
Published on: January 17, 2020
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The development of chiral nematic mesoporous materials
Joel A Kelly1, Michael Giese, Kevin E Shopsowitz
1Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
Accounts of Chemical Research
|April 4, 2014
Summary
Cellulose nanocrystals (CNCs) form chiral nematic liquid crystals, enabling the creation of iridescent mesoporous silica and carbon films. These advanced materials offer tunable properties for applications in optics, electronics, and sensing.
Area of Science:
- Materials Science
- Nanotechnology
- Optics
Background:
- Cellulose nanocrystals (CNCs) exhibit remarkable strength and self-assemble into chiral nematic liquid crystals.
- This liquid crystalline order is retained in solid films, creating photonic structures.
- CNCs serve as templates for novel mesoporous materials.
Purpose of the Study:
- To explore the creation of mesoporous silica and carbon films using CNC templates.
- To investigate the host-guest chemistry within these chiral nematic structures.
- To demonstrate the potential applications of these materials in optics, electronics, and sensing.
Main Methods:
- Sulfuric acid hydrolysis to obtain CNCs.
- Co-assembly of CNCs with sol-gel precursors (e.g., Si(OMe)4).
- Calcination and/or removal of cellulose template to yield mesoporous silica, organosilica, or carbon films.
- Incorporation of nanoparticles and polymers for host-guest studies.
Main Results:
- Formation of iridescent, chiral nematic mesoporous silica and organosilica films with tunable pore sizes (~3-10 nm).
- Development of mesoporous carbon films suitable for supercapacitor electrodes.
- Demonstration of tunable optical properties, including selective light reflection and circular dichroism signals upon guest incorporation.
- Creation of centimeter-scale freestanding films with potential for optical filters, reflectors, membranes, and sensors.
Conclusions:
- CNC templating provides a versatile route to chiral nematic mesoporous materials.
- These materials possess unique optical and structural properties derived from the CNC template.
- The developed materials show promise for advanced applications, including energy storage, optical devices, and chemical sensing.
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