Effective dispersal of CNTs in the fabrication of electrodeposited nanocomposites

This study addresses the issue of carbon nanotube (CNT) agglomeration during the fabrication of electrodeposited metal–CNT coatings. A new means of assessing dispersion stability of CNTs within a Watts electrolyte via visible light spectrometry is outlined and used to demonstrate the extent of improved dispersibility of CNTs when subjected to a well-known surface modifying acid-treatment. Varying sonication was performed to control the dispersal state of CNTs within the electrolyte during electrodeposition using untreated and acid-treated CNTs. It was found that a Watts electrolyte containing acid-treated CNTs required significantly lower sonication intensity to maintain effective dispersal during electrodeposition, facilitating the fabrication of Ni–CNT coatings containing higher volume fractions of homogenously dispersed CNTs that exhibit superior mechanical properties.

Research highlights
► A Visible light spectrometry method for assessing CNT dispersal in an electrolyte is presented.
► Untreated CNTs rapidly agglomerate in a standard Watts electrolyte.
► Deposition of CNT agglomerates results in inhomogeneous, rough and porous Ni-CNT coatings.
► The intense sonication required to break-up CNT agglomerates reduces CNT deposition efficiency.
► CNT acid treatment reduces the sonication intensity required for CNT dispersal in the electrolyte.