Carbon nanotube-cellulose ink for rapid solvent identification

In this work, a conductive ink based on microfibrillated cellulose (MFC) and multiwalled carbon nanotubes (MWCNTs) was used to produce transducers for rapid liquid identification. The transducers are simple resistive devices that can be easily fabricated by scalable printing techniques. We monitored the electrical response due to the interaction between a given liquid with the carbon nanotube-cellulose film over time. Using principal component analysis of the electrical response, we were able to extract robust data to differentiate between the liquids. We show that the proposed liquid sensor can classify different liquids, including organic solvents (acetone, chloroform, and different alcohols) and is also able to differentiate low concentrations of glycerin in water (10-100 ppm). We have also investigated the influence of two important properties of the liquids, namely dielectric constant and vapor pressure, on the transduction of the MFC-MWCNT sensors. These results were corroborated by independent heat flow mea-surements (thermogravimetric analysis). The proposed MFC-MWCNT sensor platform may help paving the way to rapid, inexpen-sive, and robust liquid analysis and identification.

Automated summary

A conductive ink based on microfibrillated cellulose (MFC) and multiwalled carbon nanotubes (MWCNTs) was utilized to produce transducers for rapid liquid identification. These transducers are resistive devices that can be easily fabricated using scalable printing techniques. By monitoring the electrical response and employing principal component analysis, the proposed liquid sensor successfully differentiated between different liquids and even low concentrations of glycerin in water. The MFC-MWCNT sensor platform holds promise for rapid, inexpensive, and robust liquid analysis and identification.