Dispersion of Boron Nitride Nanotubes in Aqueous Solution by Simple Aromatic Molecules

Abstract

We report that the simple aromatic molecules successfully disentangle and disperse multi-walled boron nitride nanotubes (BNNTs) in aqueous solutions through pi-pi stacking interactions. Aromatic molecules such as derivatives of naphthalene, anthracene, and pyrene were used as dispersants and components for construction of nanohybrids. Spectroscopic analyses of water-dispersed BNNTs revealed that not only numbers of aromatic rings but also substituted functional groups were essential for dispersion capabilities. It was suggested that greater numbers of aromatic rings and a carboxylic acid as the substituted group showed higher dispersion capabilities among the molecules used in this study. Detailed microscopic analyses using atomic force microscopy and transmission electron microscopy showed certain isolation capabilities of the aromatic molecules for BNNTs in aqueous solution. Moreover, fluorescence spectra indicated that BNNTs and the aromatic molecules have different electronic states after hybrid formation. Our results using the simple aromatic molecules will be utilized as a basic data for dispersion of BNNTs and construction of disentangled BNNT nanohybrids effectively.

Stability of Halloysite, Imogolite, and Boron Nitride Nanotubes in Solvent Media

“…However, only positively charged agents (e.g., poly-L-lysine and poly-ethyleneimine), organic amines, or chemical species able to make π-stacking and hydrophobic interactions showed good results [73]. Synthetic structures with aromatic rings (2-naphthalenecarboxylic acid, 9-anthrancecarboxylic acid, 1-pyrenecarboxylic acid, 1-aminopyrene, and 1-hydroxypyrene) [74] and polymers containing aromatic subunits, polyaniline, Noncovalent reactions are the most frequently used approach for the surface functionalization of BNNTs [73]. However, only positively charged agents (e.g., poly-L-lysine and poly-ethyleneimine), organic amines, or chemical species able to make π-stacking and hydrophobic interactions showed good results [73].…”

“…However, only positively charged agents (e.g., poly-L-lysine and poly-ethyleneimine), organic amines, or chemical species able to make π-stacking and hydrophobic interactions showed good results [73]. Synthetic structures with aromatic rings (2-naphthalenecarboxylic acid, 9-anthrancecarboxylic acid, 1-pyrenecarboxylic acid, 1-aminopyrene, and 1-hydroxypyrene) [74] and polymers containing aromatic subunits, polyaniline, poly(p-phenyleneethynylene), polythiophene, poly(xylydienetetrahydrothiophene) and poly(sodium styrene sulfonate) [73,75] interacted with the sidewall of BNNTs via π-π stacking and created stable dispersions. It was shown that poly(p-phenylene) derivatives have the most interesting potential to disperse BNNTs among studied polymers [75].…”

Surfactant-assisted individualization and dispersion of boron nitride nanotubes

“…Researchers have attempted to overcome this barrier in a variety of ways, including covalent/non-covalent functionalization, [13][14][15][16][17][18] polymer or peptide wrapping, [19][20][21][22][23][24] co-solvent systems, 25 surfactants, [26][27][28] strong acids, 12,29 and other aromatic and biomolecules. 9,10,[30][31][32][33][34] One promising way to disperse BNNTs into aqueous solution is through the use of surfactants. Surfactants are amphiphilic compounds that, when used at high enough concentrations (i.e.…”

Boron Nitride Nanotubes as Filler for Resin-Based Dental Sealants

“…Indeed, the aromatic groups present in Bis-GMA may have increased the interaction between the polymeric matrix and the fillers. This is because BNNTs’ sidewalls display an affinity to chemical compounds with aromatic groups due to the π-stacking mechanism or hydrophobic interactions 19,20 . For this reason, BNNTs were mixed with Bis-GMA prior to the addition of TEGDMA during the preparation of the experimental RBS tested in this study.…”