Thermal conversion enhancement of reconstituted tobacco via graphene-TOCNF coated thermally conductive fibrous substrate

The thermal conversion characteristics of reconstituted tobacco (RT) are critically linked to the aerosol release in heated tobacco products (HTPs). The low thermal conversion efficiency and undesirable pyrolysis constituents of RT hinder its value in advanced applications. To address this, we developed a multi-coating strategy that introduces an efficient thermal conduction pathway into the RT system. Graphene was homogeneously encapsulated within a 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofiber (TOCNF) to form a G/TOCNF composite, which was then coated onto a fibrous substrate (FS) to fabricate a thermally conductive layer. This functional fibrous material served as a substrate for an aerosol-generating matrix to form the final RT. With a graphene loading of 0.8 wt%, the thermal conductivity of the coated substrate increased by 0.14 W/(m·K). More importantly, this enhanced thermal management significantly accelerated the pyrolysis kinetics of RT. Thermogravimetric analysis revealed a 19.62% increase in total mass loss and a higher peak mass loss rate for the G/TOCNF-0.8 sample compared to the control. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis demonstrated a significant reduction in harmful heterocyclic substances, thereby establishing a predictive framework to evaluate the impact of the modified hydrogel on pyrolytic products. Consequently, the total thermal conversion rate of the G/TOCNF-0.8 RT increased by 11.81% at 260 °C. This study confirms that the G/TOCNF coating not only improves filler dispersion and heat transfer but also effectively enhances the thermal conversion efficiency of aerosol, offering a promising strategy for developing heat-responsive controlled-release systems based on engineered fibrous carriers.