Fluorescent Dyes as Carbon Nanotubes Stabilizers in Miniaturized Temperature Sensors

Carbon nanotubes (CNTs) are well known allotropes of carbon that are nowadays widely studied as their unique (thermal, electrical) properties can find application in materials science and frontier technologies. However, both single walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs) tend to agglomerate, deeply limiting their performances. It is therefore important to stabilize the CNTs dispersions either by chemical modification of their surface or by interaction with species that are bound to the surface by van der Waals forces and stacking interactions). In the frame of the study of the optical, metal ion binding, and dispersing properties of different types of perylene dye derivatives, we have analysed if the Pery-MeI dye could efficiently disperse MWNT solutions. The results obtained indicated that the mixtures are indeed stable. These are used to cast miniaturized sensors that can sense temperature with promising results: very good reproducibility, temperature coefficient comparable to that of common thermistors and improved performances respect, for instance, to CNTs stabilization by sodium dodecyl sulphate.