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

#### **Edyta Turek, Bogumila Kumanek, Slawomir Boncel and Dawid Janas \***

Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, B. Krzywoustego 4, 44-100 Gliwice, Poland; ea.turek@o2.pl (E.T.); Bogumila.Kumanek@polsl.pl (B.K.); Slawomir.Boncel@polsl.pl (S.B.)

**\*** Correspondence: Dawid.Janas@polsl.pl; Tel.: +48-32-237-10-82

Received: 18 March 2019; Accepted: 12 April 2019; Published: 14 April 2019

**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.

**Keywords:** carbon nanotubes; electrical character; aqueous two-phase extraction
