Metathesis within self-assembled gels: transcribing nanostructured soft materials into a more robust form
Jamie R Moffat1, Ian A Coates, Felicity J Leng
1Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
Langmuir : the ACS Journal of Surfaces and Colloids
|January 6, 2010
Summary
This study covalently captures self-assembled gels using alkene metathesis, creating robust, stable nanomaterials. Additives control morphology, enabling new nanofabrication possibilities for advanced materials.
Area of Science:
- Materials Science
- Polymer Chemistry
- Nanotechnology
Background:
- Self-assembled gels offer tunable properties but often lack permanent structural integrity.
- Covalent cross-linking is a key strategy to stabilize soft materials.
- Alkene metathesis provides a powerful tool for polymer modification and network formation.
Purpose of the Study:
- To report the covalent capture of self-assembled gel-phase materials using alkene metathesis.
- To investigate the influence of additives on the morphology and properties of the resulting materials.
- To demonstrate a novel nanofabrication approach for creating robust, nanostructured polymeric materials.
Main Methods:
- Gels were formed from gelators functionalized with peripheral alkene groups.
- Grubbs' second-generation catalyst was used to induce alkene metathesis within the gel network.
- Scanning electron microscopy (SEM) was employed to characterize the nanostructure of the captured materials.
- Self-sorting experiments were conducted using a mixture of cross-linkable and non-cross-linkable gelators.
Main Results:
- Alkene metathesis successfully formed covalently captured, insoluble gel materials that were robust, thermally stable, and highly swellable.
- SEM revealed nanoscale fibers within the metathesized material, which aligned into fiber bundles upon drying.
- In the presence of a non-reactive gelator, self-sorting occurred, allowing selective capture of the cross-linkable gelator.
- Additives hindered fiber bundle alignment, yielding individual nanofibers and creating more porous, swellable materials.
Conclusions:
- Alkene metathesis is an effective method for the covalent capture of nanostructured gel-phase materials.
- The morphology and properties of the resulting materials can be controlled by the judicious choice of additives and co-assembled components.
- This approach offers a versatile platform for nanofabrication, leading to the development of advanced nanostructured polymeric materials with diverse applications.
