Raman spectroscopic characterization of acid refluxed and surfactant‐assisted dispersed multiwalled carbon nanotubes on surface functionalized substrates

Abstract

AbstractThis communication focuses on the Raman spectroscopic characterization of a voltage‐controlled electrospray deposition (VCED) of multiwalled carbon nanotubes (MWCNTs) dispersed from acid refluxed and SDBS (sodium dodecyl benzene sulfonate) assisted carbon nanotube (CNT) dispersion techniques. This versatile method resulted in the direct deposition of CNT films on the surface functionalized target substrates, that is—APTES (3‐aminopropyl‐triethoxysilane) treated metal (aluminum foil), semiconducting (bare Si), and insulators (microscopy grade glass, silicon dioxide, and polymethyl methacrylate or PMMA)—used in this study. During the voltage‐controlled deposition process itself, the spray area and thickness of the MWCNT films on a substrate can be easily manipulated. In this work, CNT thin films of 40‐70 nm to 3‐7 μm were produced as a function of deposition time, with excellent packing density and surface coverage. The precise thickness control of the CNT deposits on each target substrate was achieved by meticulously calibrating the mechanics of the voltage‐controlled spray system, for example, inter‐electrode distance between the target surface and the nozzle, electric field, and flow rate of the CNT solution feed, in addition to the concentration of the CNT solution and the deposition time. These overall experimental results bode well for use of this technique in a wider range of applications where CNTs films with controlled thicknesses are required.