Noncovalent functionalization of boron nitride nanotubes using water-soluble synthetic polymers and the subsequent preparation of superhydrophobic surfaces

An experiment was conducted to demonstrate that various water-soluble synthetic polymers are able to disentangle and disperse boron nitride nanotubes (BNNTs) in an aqueous phase without forming covalent bonds. Five types of water-soluble polymers were tested, including a conjugated poly(p-phenylene) derivative ((-)PPP) and four other polymers, poly(xylylene tetrahydrothiophenium chloride) (PXT), poly(sodium styrene sulfonate) (PSS), poly(sodium vinyl sulfonate) (PVS) and poly(sodium acrylate) (PAA). Both the dispersing and functionalizing of BNNTs were dependent on the chemical structure of the individual synthetic polymers. Specifically, (-)PPP showed the greatest potential for dispersing BNNTs in an aqueous phase. The supernatant after centrifugation was slightly turbid, suggesting the presence of dispersed BNNTs. Fourier transform infrared (FT-IR) absorption spectra showed other changes in the absorption peaks that were assigned to BNNTs and (-)PPP suggesting that BNNTs are successfully functionalized by (-)PPP, mainly via π-π stacking interactions.