Applications based on carbon nanotubes (CNTs) require fine-tuning of their properties, for example in chemical sensors where they need to be made selective for a particular family of target molecules. Functionalisation can be achieved either covalently or non-covalently. In the first strategy, chemical groups (typically carboxyl and hydroxyl) are introduced to the surface of CNTs using appropriate acids, bases or oxidising agents. Covalent functionalisation creates strong covalent bonds, but this alters the electronic properties of the CNTs, which is particularly true for single-walled carbon nanotubes (SWCNTs). In fact, SWCNTs are 1D cylindrical carbon single atomic layer materials in which the delocalised π-electron density is a critical parameter governing their electronic properties. In contrast, non-covalent functionalisation involves the adsorption of molecules onto the surface of SWCNTs through weak van der Waals interactions, π-π stacking or other non-covalent forces. Wrapping functional polymers around SWCNTs is part of this second strategy. This method preserves the electrical properties of the SWCNTs and, in the meantime, can help to create stable suspensions in liquids that can be used as functional inks for subsequent printing on various substrates. Optimising the optimal stoichiometry between CNTs and adsorbed polymers is therefore of crucial interest. On the one hand, excessive polymer loading can disrupt the intrinsic electronic structure of the SWCNTs, affecting their conductivity. On the other hand, insufficient polymer loading will limit the sensitivity and selectivity of the resulting material. Methods to determine polymer/SWCNT stoichiometry are well described in the literature, but adsorption isotherms are less reported and only in the solid phase. None of these studies demonstrate the applicability of isothermal modelling for low concentrations of SWCNTs in the solution phase. To fill this gap in the literature, in this study we report a method for determining the surface coverage of SWCNTs by two different functional polymers, PVT-118 (a poly(vinyl triazole)) and FFUR (a polyfluorene). Fluorenes and carbazoles are particularly relevant groups because their properties can be finely tuned by the choice of appropriate substituents and neighbouring functions, but also because their high sensitivity to their chemical environment makes them valuable for chemical sensing applications. We will also highlight the fact that our experimental approach can be adapted to any type of polymer for the preparation of SWCNT-based polymer composite inks, for a wide range of applications.