Composite materials have the ability to be used in many different facets; however, there are limitations to this, as many properties cannot sustain new applications. Their strength wears down, the material becomes weaker, and the composite ends up failing. Many have researched how to allow for new composites that can be utilized in new ways. Due to this, there has been an increased demand for high-performance materials that contain particular desired properties and multi-functional capabilities.
The drive for these is to have the potential to be used in a wide range of applications. This can be achieved by combining nanoscience and nanotechnology with existing composite science and technology. Through the combination, there can be a new material systems developed with improved properties, multi-functionality, and performance for varying applications.
The concern with traditional structural composites lies in their weak through-the- thickness and interlaminar properties. Because of the through-the-thickness’ and interlaminar’s dependence upon the weak matrix, there exists poor qualities in these areas. These weaknesses often lead to failures in the composites. In the case of failure, there can be an endangerment of someone’s life. Researchers believe that this possibility must be corrected and composites must be developed in new ways to divert any issues that materials currently face.
APPLICATION AND ADVANTAGES
Carbon Nanocomposites are capable of reinforcing throughthe- thickness in different composite materials. Their quality of using high density arrays of vertically aligned carbon nanotubes (CNT), the fracture toughness, flexural modulus and strength, flexural toughness, damping, coeficient of thermal expansion, and through-the- thickness thermal and electrical conductivities were improved. In addition, the adhesion of adjacent fabric layers can be improved through the use of CNT nanoforests that are normal to the laminae.
Carbon Nanocomposites are capable of reinforcing through the thickness in different composite materials. Their quality of using high density arrays of vertically aligned carbon nanotubes (CNT), the fracture toughness, flexural modulus and strength, flexural toughness, damping, coeficient of thermal expansion, and through-the- thickness thermal and electrical conductivities were improved. In addition, the adhesion of adjacent fabric layers can be improved through the use of CNT nanoforests that are normal to the laminae.
In the typical application of reinforcements on composites, they are produced in bundle form. Then they are woven together in a way that creates fabrics with varing textures and composition. Traditional composites are not develoiped with nanoscale details at work. The technology that Dr. Askari has developed allows for a new implementation that mimics the highperformance natural fibrous materials in nature. For example, the reinforcements and their placement can be easily explained as to be similar to a bird’s nest or spider net
These reinforcements are introduced in between the fiber bundles within the woven fabrics. There has not been a time where the incorporation of reinforcements were done in between individual fiber strands. Instead, they would be implemented among the different bundles. This method does not give the composite the strength it requires to succeed. Materials weaken under pressure when the etangled nanotubes are not present in a fiber.
Nanostructured materials provide large surface areas and interfaces that participate in chemical reactions, form chemical bonds with adjacent materials, and provide attractive Van der Waals forces. Individual fiber strands and the matrix can also be entangled with microfiber strands and the cured matrix. This inter-locking and ntanglement creates high mechanical, thermal, and electrical properties in composites. Ultimately, this leads to higher durability and increased strength when exposed to harsh conditions.
Dr. Davood Askari is an Assistant Professor of Mechanical Enineering at Wichita State University. Dr. Askari has attended Sharif University of Technology, Eastern Mediterranean University, and University of Hawaii at Manoa. His research interests include: design, modeling, analysis, fabrication, and testing/ characterization of many materials. These materials are composites and nanocomposites, thin films, hydrophobic surfaces, carbon nanostructures, NanoNeedles, and 3D nanostructures, devices and systems.