However, the regioselectivity for the liquid-solid reaction clearly suffers at the higher temperature, compared to the gas-solid reaction. When pyridine, as catalyst, is used the regioselectivity clearly decreases -At RT the crystallinities are largely preserved. However, CTA motifs become apparent, from the acetate region in the NMR spectra. This is a strong indication that CTA is forming on the surface of the CNCs, which is clearly more progressive at 80 °C. In the case of the DABCO-catalysed reaction, the samples colourise at RT and quickly blacken at 80 °C, where CTA formation is predominant.