Aqueous dispersion of SWCNT using vegetable oil-based 3-Arm star oligomer: mechanistic investigation and its functional application

Abstract

Aqueous dispersions of single-walled carbon nanotubes (SWCNTs) are crucial for the sustainable development of next-generation materials. In this study, we report the synthesis of a novel vegetable oil-based dispersant for stabilizing SWCNTs in water. Castor oil (CO) was modified via the ring-opening polymerization of glycidyl methacrylate (GMA) to produce a 3-arm star oligomer (CG2) with a weight-average molecular weight (M_w) of 1756 g mol⁻¹. UV-vis, DLS, HRTEM, and FESEM analyses confirmed that CG2 efficiently interacted with SWCNTs and dispersed them in water at CG2/SWCNT ratios above 4 : 1 (w/w). The interaction mechanism was investigated through UV-Vis and FTIR analyses and validated by density functional theory (DFT) calculations. Binding energy evaluations at various potential sites provided insight into the strength of these interactions, while atoms-in-molecules (AIM) analysis revealed their underlying nature. Finally, CG2–SWCNT dispersions (10 : 1, w/w) were coated onto a cellulose paper, achieving a conductivity of 0.4 S m⁻¹ and wide temperature (−28 °C to 173 °C) stability. The conductive paper was successfully applied in prototype glove fabrication and demonstrated functionality in touchscreen operations at both ambient and low temperatures. This sustainable dispersant thus offers a promising route for developing conductive surfaces with potential applications in cold environments and for strategic sectors.