Covalent Functionalization of Boron Nitride Nanotubes via Reduction Chemistry

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Boron nitride nanotubes (BNNTs) possess unique properties but suffer from low chemical reactivity.
• This inherent inertness hinders their functionalization for targeted applications.

Purpose of the Study:

• To investigate covalent functionalization of BNNTs using reduction chemistry.
• To explore enhancing BNNT reactivity through negative charging.

Main Methods:

• Density functional theory (DFT) calculations to determine electron affinity and radical binding energies.
• Experimental covalent alkylation of BNNTs using 1-bromohexane on reduced and neutral samples.
• Thermogravimetric analysis (TGA) to quantify functionalization.

Main Results:

• DFT calculations predicted a 5.5-fold increase in reactivity of reduced BNNTs towards NH2 radicals.
• Excess electrons in reduced BNNTs localize at boron sites, facilitating covalent bond formation.
• Experimental results showed significant weight loss (12-14%) in reduced BNNTs after alkylation, unlike neutral BNNTs.

Conclusions:

• Reduction chemistry is a viable strategy to enhance BNNT reactivity for covalent functionalization.
• This approach offers an effective route for tailoring BNNTs for specific technological applications.