Fig. 2: Spectroscopic composition of the fibres.

a Mass spectrum recorded with a mass quadrupole spectrometer with hydrogen introduced into the system (black line) and without hydrogen introduced into the system (red line—shifted down for clarity). The more intense unlabelled peaks, at 40 and 20 m/z, correspond to Ar (the sputtering gas) and its double ionisation, respectively, whereas the peaks at 36 and 38 m/z are due to stable Ar isotopes. b GC–MS chromatogram obtained from a very dilute solution of the fibres in acetonitrile collected from an Au substrate (red), showing a distribution of chain lengths centered around C₂₇ (peak marked * corresponds to a known line from Irganox additive from the micropipette tip). A reference spectrum of a C₂₈ linear alkane standard (green) was included for comparison. c Representative Raman spectrum recorded from a highly covered sample deposited on a SiO_x substrate, with the most characteristic vibrational modes indicated. d AFM topography image of a fibre-rich area on an Au substrate recorded with AFM-IR (spatial resolution 10 nm) and (e) IR spectrum obtained at the marked position in the previous image, from a single nanofiber at 10 nm resolution, with methyl- and methylene-group vibrations indicated.