Manufacture of Networks from Large Diameter Single-Walled Carbon Nanotubes of Particular Electrical Character

Abstract

We have demonstrated that the aqueous two-phase extraction (ATPE) can differentiate between large diameter single-walled carbon nanotubes (CNTs) by electrical character. Introduction of “hydration modulators” to the ATPE machinery has enabled us to isolate metallic and semiconducting CNTs with ease. We have also shown that often there is a trade-off between the purity of the obtained fractions and the ability to separate both metallic and semiconducting CNTs at the same time. To isolate the separated CNTs from the matrices, we have proposed a method based on precipitation and hydrolysis, which can eliminate the need to use lengthy dialysis routines. In the final step, we prepared thin free-standing films from the sorted material and probed how electrical charge is transported through such macroscopic ensembles.

Thermoelectric Properties of Thin Films from Sorted Single-Walled Carbon Nanotubes

“…At present, one of the pressing challenges of this field is to devise straightforward protocols of large-scale separation of SWCNTs by electrical character to open several potential applications for power engineering. So far, several ways of separation by the electrical nature [ 29 , 30 , 31 ] were developed to obtain metallic or semiconducting base materials for conducting wires [ 32 ] or thermogenerators [ 33 ], respectively.…”

Simple Method to Improve Electrical Conductivity of Films Made from Single-Walled Carbon Nanotubes

“…That is a multidimensional problem, which results from a range of technological constraints, which need to be tackled. Firstly, electrical conductivity of individual CNTs depends on the way they are “rolled-up” from a graphene sheet [12], so appropriate methods of structure control have to be established (either at the synthesis stage or during post-processing [13]). Secondly, CNTs should be assembled into networks such as fibers, wires or coatings in the right way [9].…”

“…Most commonly, isotropic CNT films are produced and unfortunately they have inferior electrical conductivity. The presence of impurities or improper charge transfer often push their electrical conductivity below 500 S/cm [13,22,23]. That is why new solutions are being searched for in order to make full use of the potential existing in CNTs.…”

Functional Nanostructures for Sensors, Optoelectronic Devices, and Drug Delivery

“…The scope of the Special Issue “Functional Nanostructures for Sensors, Optoelectronic Devices, and Drug Delivery” was to provide an overview of the current research activities in the field of nanostructured materials, with a particular emphasis on their potential applications for sensors [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ], optoelectronic devices [ 10 , 11 , 12 , 13 , 14 , 15 ], and biomedical systems [ 16 , 17 , 18 ]. The Special Issue welcomed the submission of original research articles [ 1 , 2 , 3 , 4 , 5 , 6 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ] and comprehensive reviews that demonstrated or summarized significant advances in the above-mentioned research fields. Next, the Special Issue collected fifteen selected original research papers and three comprehensive reviews [ 7 , 8 , 18 ] on various topics of nanostructured materials and relative characterization spanning from fundamental research to technological applications.…”

“…The introduction of hydration modulators (H 2 O 2 and PEGme) significatively improved the resolution of the one-step system. Moreover, to isolate the separated CNTs from the matrices, the authors proposed a method based on precipitation and hydrolysis, which is easier than lengthy dialysis routines [ 15 ].…”