Colloid‐Assisted Self‐Assembly of Robust, Three‐Dimensional Networks of Carbon Nanotubes over Large Areas

Abstract

Natural materials, such as bone and spider silk, possess remarkable properties as a result of sophisticated nanoscale structuring. They have inspired the design of synthetic materials whose structure at the nanoscale is carefully engineered or where nanoparticles, such as rods or wires, are self-assembled. Although much work has been done in recent years to create ordered structures using diblock copolymers and template-assisted assembly, no reports describe highly ordered, three-dimensional nanotube arrays within a polymeric material. There are only reports of two-dimensional network structures and structures on micrometer-size scales. Here, we describe an approach that uses plasticized colloidal particles as a template for the self-assembly of carbon nanotubes (CNTs) into ordered, three-dimensional networks. The nanocomposites can be strained by over 200% and still retain high conductivity when relaxed. The method is potentially general and so may find applications in areas such as sensing, photonics, and functional composites.

Is severe macrosomia manifested at 11–14 weeks of gestation?

“…Based on our previous findings,14 we have created ordered monolayers of monodispersed colloidal particles containing honeycomb‐like networks of CNTs. In our previous work, we have shown that in three dimensions, such precise assembly of CNTs is facilitated by tuning the interface between the polymer and the CNTs using a nonionic surfactant.…”

Stretchable Conductive Networks of Carbon Nanotubes Using Plasticized Colloidal Templates

“…It is apparent that the polymer particles undergo deformation, becoming more elongated in the direction of applied stress (Figures 2B-E). In previous work, we have shown qualitatively that for 3D composites, there is a resulting mapping of the nanotube assembly with polymer deformation (Jurewicz et al, 2010).…”

“…Therefore, for this work, we have chosen two composites containing either 0.2, 0.5, or 1 wt.% of SWNTs in the final dry samples. For SWNTlatex composite films in this concentration regime, we expect to see SWNT bundles forming complete networks within the latex crystal template well above the electrical percolation threshold (Jurewicz et al, 2010). Moreover, at large strain levels, these composites maintain their viscoelastic properties and still conduct electricity.…”

“…From our previous work on stretchable composites based on CNTs assembled in the interstitial sites of the polymer latex matrix, we learned that the electrical percolation threshold for a composite with a segregated microstructure is as low 0.12 wt.% (Jurewicz et al, 2010(Jurewicz et al, , 2011. For such a composite material to maintain its desirable properties under deformation, network connectivity must be maintained.…”

“…Templated self-assembly of single-wall carbon nanotubes (SWNTs) into low-percolation conductive films has been demonstrated previously (Kim et al, 2008;Jurewicz et al, 2010Jurewicz et al, , 2011Jurewicz et al, , 2012Worajittiphon et al, 2010). This technique reduces the filler weight fraction required to form percolating conductive pathways by exclusion from the latex polymer volume during initial film formation.…”