Electrical Conductivity and Wettability of Nanofluids Prepared by Nanocomposite of MWCNTs and Dialkyl Pentasulfide

Background: Multi-walled carbon nanotubes (MWCNTs) were filled with dialkyl pentasulfide (DPS) to prepare MWCNTs-DPS composite (nanocomposite) additives for use in nanofluid- based machining. Methods: The nanocomposite was prepared by employing a liquid phase wet chemistry method, and was then added in pure water with a surfactant to form the nanofluids. The present study comprehensively reveals the effects of additive concentration, acid treatment time, testing temperature and electrowetting conditions on the electrical conductivity and wettability of nanofluids. Results: The nanocomposite was successfully produced with a maximum filling rate of 27.4%. Its additives displayed an optimal performance at a concentration of about 0.1%. Consequently, the electrical conductivity and wettability of the nanofluids were increased by over 13.7% and 6.35%, respectively in comparison with individual MWCNTs additives. Under the electro-wettability conditions, the wetting performance of the nanofluids produced by the nanocomposite increased with the increase in charging voltage. Moreover, due to higher conductivity and greater charge capacity, the nanofluids with a higher additive concentration displayed better wetting performance. Conclusion: The modification and filling enhanced properties such as the surface activity, electrical conductivity and capacitance of the MWCNTs, thereby improving the performance.