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pH‐Switchable Water‐Soluble Boron Nitride Nanotubes
Author(s) -
Guan Jingwen,
Kim Keun Su,
Jakubinek Michael B.,
Simard Benoit
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201801544
Subject(s) - boron nitride , solubility , aqueous solution , boron , bromine , hydrogen bond , yield (engineering) , chemistry , inorganic chemistry , materials science , chemical engineering , organic chemistry , molecule , engineering , metallurgy
Abstract The first example of aqueous solutions of boron nitride nanotubes (BNNTs) with switchable stability and without use of surfactants is demonstrated. The as‐produced boron nitride nanotubes are both purified and solubilized through an environmentally friendly and scalable approach using water extraction and liquid bromine treatment. This treatment effectively removes elemental boron particles and excess bromine reacts with BNNTs, inducing B−N bond cleavage on the BNNT surface to yield hydroxyl (OH) and amino (NH 2 ) functionalized BNNTs. The resulting functionalized BNNTs form stable aqueous solutions around neutral pH (4 < pH < 8), but readily precipitate in other pH ranges. This switchable solubility is explained in terms of the capability of the functional groups (OH and NH 2 ) to form hydrogen‐bonding networks in water. Further, the solubility differences in selected polar organic solvents have been utilized to prepare functionalized BNNTs with higher purity.