Site-Specific Controlled Growth Of Coiled Lambda-Shaped Carbon Nanofibers For Potential Application In Catalyst Support And Nanoelectronics

Carbon nanofibers (CNFs), in particular branched ones, raise high interest because of their potential for nano-electronics, catalyst presentation, and applicability as dry adhesives. Here, we present a facile method based on an open ethanol flame in a microchannel for the controlled growth of coiled lambda-shaped carbon nanofibers (c lambda CNFs). The c lambda CNFs consist of two coiled foot CNFs anchored to the substrate and a noncoiled head CNF. The number of twists in the helical structure of the foot CNFs is always the same number and in the opposite direction of rotation for a given c lambda CNF. The growth position of the c lambda CNFs on a substrate can be controlled by targeted deposition of nickel salt via an atomic force microscopy cantilever. An extensive characterization of the c lambda CNFs allows us to understand the growth process and to develop a model explaining the observed features of the structures. The presented facile but controlled fabrication process for c lambda CNFs offers a promising route for targeted synthesis of a novel carbon structure with chiral subcomponents for experimental and application use as in site-specific growth of branched CNFs for nanoelectronics or local presentation of catalysts.