Controlling the Degree of Functionalization: In‐Depth Quantification and Side‐Product Analysis of Diazonium Chemistry on SWCNTs

Abstract

We present an in‐depth qualitative and quantitative analysis of a reaction between 4‐iodobenzenediazonium tetrafluoroborate and single‐walled carbon nanotubes (SWCNTs) via thermogravimetric analysis coupled with mass spectrometry (TG‐MS) or a gas chromatography and mass spectrometry (TG‐GC‐MS) as well as Raman spectroscopy. We propose a method for precise determination of the degree of functionalization and quantification of physisorbed aromates, detaching around their boiling point, alongside covalently bonded ones (cleavage over 200 °C). While the presence of some side products like phenol‐ or biphenyl species could be excluded, residual surfactant and minor amounts of benzene could be identified. A concentration‐dependent experiment shows that the degree of functionalization increases with the logarithm of the concentration of applied diazonium salt, which can be exploited to precisely adjust the amount of aryl addends on the nanotube sidewall, up to 1 moiety per 100 carbon atoms.

Synthetic control over the binding configuration of luminescent sp3-defects in single-walled carbon nanotubes

“…16), with similar results. It is noteworthy that it was not possible to employ thermogravimetric analysis coupled with mass spectrometry 45 to further confirm the nature of attached functional groups due to the necessarily low defect density and limited amount of purified (6,5) SWNTs.…”

Grafting of Diazonium Salts on Surfaces: Application to Biosensors

“…Carbon nanotubes (CNT). A detailed investigation of the grafting of 4-iodobenzenediazonium on SWCNTs (single-walled carbon nanotubes) showed that (i) the bonded aryl groups were very stable, as they cleaved above 200 • C, (ii) a logarithmic correlation between the degree of functionalization and diazonium concentration was observed, and (iii) the maximum surface concentration was measured as one aryl group per 100 carbon atoms [30].…”

Reversible functionalization and exfoliation of graphite by a Diels–Alder reaction with furfuryl amine

“…The TGA is also a suitable measurement to calculate the degree of the functionalization (DOF) of the G-FA product. 51 TGA pattern for G-FA shows 2.1% weight loss at 250 centigrade degrees, which can be used to calculate DOF. Hence, furfuryl amine has been attached to the graphene layers with high DOF = 0.26.…”