Synthesis of boron nitride nanotubes from unprocessed colemanite

Abstract

SummaryColemanite (Ca2B6O11·5H2O) is a natural and new precursor material for the synthesis of boron nitride nanotubes (BNNTs). BNNTs have been synthesized from unprocessed colemanite for the first time. The reaction parameters such as time, catalyst type, catalyst amount and temperature were optimized. It was found that the BNNT formation follows the base growth mechanism, which was initiated with a complex of boron nitride (BN) and iron atoms. The obtained BNNTs were characterized by using SEM, TEM, and spectroscopic techniques such as UV–vis, Raman, FTIR and XRD. The BNNTs were randomly oriented and multi-walled with an outer diameter of 10–30 nm and a wall thickness of 5 nm. This novel BNNT synthesis method can be used to obtain high yield, low cost and pure BNNTs.

Electrically insulating polymeric nanocomposites with enhanced thermal conductivity by visible-light curing of epoxy-boron nitride nanotube formulations

“…The epoxy matrix was selected because of good mechanical performance and good adhesion together with electrically insulating properties . However, it has very poor thermal conductivity . Higher thermal conductivity can be achieved by the use of suitable electrically insulating fillers such as BNNTs characterized by high thermal conductivity and excellent high‐temperature resistance, as discussed in the Introduction.…”

Interaction of carbohydrate modified boron nitride nanotubes with living cells

“…BNNTs were synthesized from colemanite based on a chemical vapor deposition (CVD) method, and purified as reported earlier [23]. For hydroxylation, 100 mg of pure BNNTs were added into 10 mL of 30% H 2 O 2 solution, and the mixture was sonicated at 25 • C for 1 h. Then, the mixture was refluxed for 48 h at 110 • C while stirring.…”

Boron Nitride Nanotubes and Layer‐By‐Layer Polyelectrolyte Coating for Yeast Cell Surface Engineering

“…The white powder,t hat includes BNNTsa tt he top of alumina boat, was eventually collected. The hydroxylation of the BNNTsw as achieved with H 2 O 2 as reported elsewhere: [14] 100 mg of pure BNNTsw ere sonicated at 25 8Cf or 1h our into 10 mL of a3 0% H 2 O 2 solution. The obtained BNNT-OHs were precipitated by centrifugation (15 min, 10 000 rpm), washed in pure H 2 Ofive times, and eventually dried at 60 8C.…”

“…[14] Briefly,2g of colemanite and 160 mg of Fe 2 O 3 were dispersed in 2mLo fp ure H 2 Oa t1 00 8C, and thereafter placed into at ubular furnace (Protherm, Furnaces PTF 14/50/450) for 3h at 1280 8Ci naN H 3 atmosphere to achieve BNNT formation. The white powder,t hat includes BNNTsa tt he top of alumina boat, was eventually collected.…”

“…They were first functionalized with reactive groups (i.e., ÀOH groups), which bind at the edges and at the defects on the surfaces of BNNTs. [14] Clearly, chemically functionalized BNNTsc an electrostatically interact with PEs during the encapsulation process of cells with PEs.…”