Nora Wetzold

Carbon Nanotube Areas — Printed on Textile and Paper Substrates

Mass printing processes are the key technology to produce mass products to the point of one-disposable. Carbon nanotube (CNT) based structures were prepared by flexographic printing using multi-walled carbon nanotube (MWCNT) dispersions in water. The carbon nanotubes were applied to a textile substrate made of polyester and polyamide microfilaments and to both-side coated paper to produce electrically conductive layers that can be used, for example, as heating elements. Carbon nanotube layers with sheet resistivity ranging from 0.12 to 3.00 kΩ/sq were obtained. The ratio of radiation power PS (determined according to the Stefan-Boltzmann law) of the printed layers to the electrical power spent, represents the efficiency of the system. The samples on textile substrate with a surface temperature of 169°C have an efficiency of 25%, the paper samples with a surface temperature of 93 °C have an efficiency of about 15 %.

Electrochemical responses of carbon nanotubes-based films printed on polymer substances

The electrochemical responses of novel thin films, which consist of multiwalled carbon nanotubes (MWCNTs) printed on polymer substrates, were investigated towards ferrocyanide/ferricyanide, [Fe(CN)6]3−/4− redox couple in aqueous potassium chloride solutions. With this respect, MWCNT-based films were fabricated through transfer of water-dispersed MWCNTs onto the polymer substances polyethylene terephthalate (MWCNT-PET) and polycarbonate (MWCNT-PC) by means of mass flexographic printing process. For the electrochemical studies, the techniques of cyclic voltammetry and electrochemical impedance spectroscopy were employed. The findings reveal that the MWCNT-PC films exhibit better stability in solution, less oxidation overpotential, greater oxidation current density, and larger capacitance compared to MWCNT-PET films. In addition, the MWCNT-PC films provide fewer barriers for electron transfer process and faster electrode kinetics compared to MWCNT-PET films. The results are very promising and open the possibility of using mass-printing techniques for the construction of printed MWCNT-polymer films for electrochemical applications.

Disposable Multiwalled Carbon Nanotube Printed Film Electrochemical Determination of Acetaminophen, Dopamine, and Uric Acid

A novel printed film consisting of multiwalled carbon nanotubes was fabricated on a polyethylene terephthalate substrate by means of a mass flexographic printing process. Potential applications of this film for electrochemical biosensing were examined through the oxidation of acetaminophen, dopamine, and uric acid in phosphate buffer (pH 7.0). The results demonstrate that the printed carbon nanotube film exhibits an enhanced electrochemical response toward these molecules. Dopamine and uric acid did not interfere with each other and, thus, their simultaneous determination may be performed. The results suggest the mass flexographic printing technique has potential application for the construction of low-cost, precise, and disposable multiwalled carbon nanotube films.