Dispersion Enhancement of Boron Nitride Nanotubes in a Wide Range of Solvents Using Plant Polyphenol-Based Surface Modification

Boron nitride nanotubes (BNNTs) have gained significant attention as a nanofiller additive to enhance the mechanical and thermal properties of polymer composites. However, despite the advancements in BNNT large-scale synthesis methods, the inherent hydrophobicity and the presence of van der Waals attraction hinder their potential application due to poor dispersion in polar and/or nonpolar solvents. In this communication, a facile deposition approach of plant-based polyphenols intercalated with an amine source was postulated. Given the economic advantage and ease of deposition, tannic acid (TA) was directly deposited onto the BNNT surface to enunciate hydrophilic attributes. Afterward, decylamine (DA) was introduced into the BNNT-TA (BNNT-TA–DA) to heighten the BNNT interaction with the polymeric system. The dried BNNT-TA and BNNT-TA–DA powders can be readily redispersed at various concentrations in polar and nonpolar solvents, enhancing the BNNT dispersion and interaction with the polymeric matrix to improve the composite performance. Moreover, to demonstrate the interfacial modification viability, BNNT-TA–DA was used as a filler in epoxy resin to form polymer composites. The fabricated composites displayed 26.8% tensile stress and 52.2% breakpoint of strain increases compared to those of the neat polymer at 1 wt % loading.