The experimental study of the effect of microwave on the physical properties of multi-walled carbon nanotubes

[Display omitted] •We study the microwave effect on the multi-walled carbon nanotubes (MWCNTs).•We examine the non uniform heating effect on the physical structure of MWCNTs.•We examine the purification of MWCNTs by microwave.•We analyze the thermal characteristics of microwave treated MWCNTs. This paper reports the effect of microwave on the physical properties of multi-walled carbon nanotubes (MWCNTs) where different power levels of microwave were applied on MWCNTs in order to apprehend the effect of microwave on MWCNTs distinctly. A low energy ball milling in aqueous circumstance was also applied on both MWCNTs and microwave treated MWCNTs. Temperature profile, morphological analysis by field emission scanning electron microscopy (FESEM), defect analysis by Raman spectroscopy, thermal conductivity, thermal diffusivity as well as heat transfer coefficient enhancement ratio were studied which expose some strong witnesses of the effect of microwave on the both purification and dispersion properties of MWCNTs in base fluid distilled water. The highest thermal conductivity enhancement (6.06% at 40°C) of MWCNTs based nanofluid is achieved by five minutes microwave treatment as well as wet grinding at 500rpm for two hours.