Noe Alvarez

Abstract:

This talk will report fundamental calculations and experimental studies for chemical bond formation of open-ended vertically oriented carbon nanotubes (CNTs) to copper metal surfaces.1 Chemical bonds, preferentially covalent, between metal atoms and functional groups (linkers) at the open ends of CNTs is highly desired in order to create a robust connection and anchoring the CNTs to macroscopic metal surfaces.2-3 In addition, a chemical connection between metals and CNTs is critical for wiring two metals through a single CNT.4-5 Unlike traditional methods that rely on synthesis, where good quality CNTs are grown directly on metal substrates at temperatures above 600 °C this method reports covalent bond formation at temperatures as low as 120 °C. The reported theoretical calculations demonstrate that C atoms on aminophenyl can form a bridge like covalent bonds with two adjacent Cu atoms on (100), (110), and linear bond on (111) Cu crystal lattice substrates. The aminophenyl of bonded carbon atom was employed as linker molecule to simulate intramolecular electron transport between chemically connected carbon nanotubes and copper metals in this carbon/metal hybrid materials. The strength of the bonding was experimentally evaluated by placing the hybrid (CNT/Cu) material in solution and exposing to bath sonication. To our surprise, the CNTs remained attached to the substrate even after 30 min sonication. In addition, adhesive tape was applied to remove the bonded CNT array from the metal surface. The area from where CNT arrays were removed revealed that some CNTs still remained attached to the copper surface, supporting the strong bonding to the metal. XPS, FT-IR, Raman analysis and scanning electron microscopy images support the formation of direct connections between the vertically aligned CNTs and the metal substrates. The reported covalent bond formation is expected to facilitate the application of CNTs in multiple fields such as biomaterials, electrocatalysis, sensor development and electronics.