Glass-coated individual dispersed MWNTs in Alumina & its high temperature stability

Abstract

An ultrasonication assisted sol-gel processing route for MWNTs/Alumina was proposed. Using aluminum ethoxide as an alumina precursor and ethanol/water as a solvent, the duration of the transformation from sol to gel under ultrasonication can be controlled by adjusting the water content. Purified MWNTs added under ultrasonication should be functionalized by alcohol at first and a well dispersion in alumina sol could be attained under the help of ultrasonic. With the evaporation of ethanol, sol transfers to gel and MWNTS dispersion can be kept in gel. Gel and calcine-powder show that individual MWNTs are enwrapped by amorphous alumina. As-received powders after a following heating-treatment under vacuum shows a good high stability for a glass coat formed on MWNTs. Raman results show the processing route has no obvious effect on the structure of MWNTs, even a high temperature (1273K) treatment is done under vacuum.

Keywords

MWNT / alumina / dispersion

References

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