Self-Assembled Liquid Crystal Thermoset 3-D Nano-Composites With Functionally Graded Properties

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

This grant provides funding for research into a method for fabricating a new class of three-dimensional polymer matrix nanocomposites with custom designed functionally graded properties. The objective of the research is to synthesize structural composites designed with specific regions that have different stiffness, strength, and toughness values that optimize the overall mechanical and thermal performance of the composite. The materials of interest are formed from chemically reactive liquid crystal monomers containing carbon nanotubes. Liquid crystal monomers are unique in that they can be selectively oriented by magnetic or electric fields and can then be locked in place by photoreaction of the monomers in-situ. It is anticipated that orienting the liquid crystal molecules which contain nanotubes will cause self-alignment of the nanotubes, resulting in composites that have enhanced anisotropic mechanical properties. The nanocomposites can be formed by an inkjet deposition process and it is anticipated that local variations in alignment as well as composition can be accommodated by changing the direction of the applied field during processing. Modeling the material and process will enable the custom design of three dimensional nanocomposites with superior performance for advanced applications. Using this process, it is possible to form nanotube-polymer composites that are stiffer, tougher, and at the same time lighter weight than the best available carbon fiber-epoxy composites. Fully computerized solid freeform fabrication processing via inkjet deposition could enable the direct production of nano-composites and eliminate the use of conventional casting, forging, machining, or molding processes and the use of expensive tooling. This process is fast and accurate and is potentially capable of forming large sized composite structures. The ability to produce custom shapes at will lends itself to rapid, flexible, customized production at any location such as on ships at sea for production of one-of-a-kind critical composite components.