Ultrasonic processing for dispersion of CNTs in suspension wasperformed using a Hielscher UP400S 24 kHz device (HielscherUltrasonics GmbH, Teltow, Germany), power capacity of 400 W,equipped with a Ø 22 mm cylindrical sonotrode. Output powerwas regulated by means of manual adjustment of wave ampli-tude within 25–100% of the device’s maximum capacity. Theactual power transmitted to the suspension was measured using aHielscher PowMet230 digital ultrasound energy meter. All suspen-sions where sonicated at 50% of the maximum ultrasound waveamplitude corresponding to an energy input rate of 7700 J/min[21]. Dispersant agent-assisted aqueous suspensions of CNTs wereprepared in fume hood environment according to the followingstrategy: A predetermined dispersant agent mass was initiallyadded to 1000 ml of tap water in 2000 ml capacity low-form Pyrexglass beakers and an opalescent solution indicating complete dis-solution was achieved after 60 s of magnetic stirring. The sonotrodewas subsequently fully immersed into the suspension, sonicationwas commenced and CNTs were gradually introduced into the son-icated liquid. To investigate the effect of surfactant concentrationon dispersion quality and identify the optimal surfactant/CNT ratiorequired to avoid surfactant stagnation or saturation, suspensionswith SDBS/CNT ratios of 0.5/1, 1/1 and 2/1 were prepared by varyingthe initial surfactant mass within 2.5, 5 and 10 g. For SDBS-assistedsuspensions, two CNT loadings were used, 0.5 and 1 wt% CNTs. Forviscocrete-assisted suspensions, the corresponding ratio was 1.5/1,while CNT loading varied between 0.4 and 1.6 wt%.