A microwave cured flux for the adhesion of ceramic particles using silica coated carbon nanotubes

We report the application of multi-walled carbon nanotubes (MWCNTs) to facilitate the fusing of ceramic particles together by the creation of a silica flux through localized microwave heating of the carbon nanotubes. When pre-formed Stöber SiO2 nanoparticles (120 nm) and MWCNTs are co-mixed with alumina microbeads (369 ± 47 μm) the SiO2 nanoparticles act as anchor points and attach the MWCNTs to the larger alumina surface. Upon microwave irradiation (2 × 1 min @ 1000 W) large silica plates of a few nanometers in length are formed. The localized heat that MWCNTs generate under microwave irradiation produces sintering within the silica. Mixing of preformed SiO2-coated MWCNTs with the alumina particles results in the formation of “patches” on the surface of alumina, that upon exposure to microwave irradiation causes the melting of the silica and its flow as “bridges” between the particles effectively “welding” the microbeads together. The microwave heating of the MWCNTs can be thus be used to create interaction and adhesion between particles.