Suzhou Nutpool Materials Technology Co., Ltd

Boron nitride nanotubes (BNNTs) are a unique class of light and strong tubular nanostructure

and are highly promising as reinforcing additives in ceramic materials. However, the mechanical

strength of BNNT-ceramic interfaces remains largely unexplored. Here we report the first direct

measurement of the interfacial strength by pulling out individual BNNTs from silica (silicon

dioxide) matrices using in situ electron microscopy techniques. Our nanomechanical

measurements show that the average interfacial shear stress reaches about 34.7 MPa, while

density functional theory calculations reveal strong bonded interactions between BN and silica

lattices with a binding energy of –6.98 eV nm−2

. Despite this strong BNNT-silica binding,

nanotube pull-out remains the dominant failure mode without noticeable silica matrix residues

on the pulled-out tube surface. The fracture toughness of BNNT-silica ceramic matrix

nanocomposite is evaluated based on the measured interfacial strength property, and substantial

fracture toughness enhancements are demonstrated at small filler concentrations.