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 a synthesis of 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 3arm star oligomer (CG2) with a weight-average molecular weight (Mw) of 1756. Experimentally, UV-Vis, DLS, HRTEM, and FESEM analyses confirmed that CG2 efficiently interacted with SWCNT and dispersed SWCNTs 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 cellulose paper, achieving a conductivity of 0.4 S/m and wide temperature (-18 o C to 173 o 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 regions and strategic sectors.