Critical challenges and advances in the carbon nanotube-metal interface for next-generation electronics.

Next-generation electronics can no longer solely rely on conventional materials; miniaturization of portable electronics is pushing Si-based semiconductors and metallic conductors to their operational limits, flexible displays will make common conductive metal oxide materials obsolete, and weight reduction requirement in the aerospace industry demands scientists to seek reliable low-density conductors. Excellent electrical and mechanical properties, coupled with low density, make carbon nanotubes (CNTs) attractive candidates for future electronics. However, translating these remarkable properties into commercial macroscale applications has been disappointing. To fully realize their great potential, CNTs need to be seamlessly incorporated into metallic structures or have to synergistically work alongside them which is still challenging. Here, we review the major challenges in CNT-metal systems that impede their application in electronic devices and highlight significant breakthroughs. A few key applications that can capitalize on CNT-metal structures are also discussed. We specifically focus on the interfacial interaction and materials science aspects of CNT-metal structures.

Manipulation of Fracture Behavior of Poly(methyl methacrylate) Nanocomposites by Interfacial Design of a Metal-Organic-Framework Nanoparticle Toughener.

The interfacial region between nanoparticles and polymer matrix plays a critical role in influencing the mechanical behavior of polymer nanocomposites. In this work, a set of model systems based on poly(methyl methacrylate) (PMMA) matrix containing poly(alkyl glycidyl ether) brushes grafted on 50 nm metal-organic-framework (MOF) nanoparticles were synthesized and investigated. By systematically increasing the polymer brush length and graft density on the MOF nanoparticles, the fracture behavior of PMMA/MOF nanocomposite changes from forming only a few large crazes to generating massive crazing and to undergoing shear banding, which results in significant improvement in fracture toughness. The implication of the present finding for the interfacial design of the nanoparticles for the development of high-performance, multifunctional polymer nanocomposites is discussed.