Nanoparticles type Base fluid Synthesis process Particle loading (vol. %) Particle size (nm) Dispersion method Stability Ref. SiO2 Water Two-step 10 NR 3-Glycid oxyl proyl tri-methy oxy silane (mass ratio of silane to silica = 0.115) + solution kept at 50°C for 12 hours 12 months [2 ] SiO2 Deionized water Two-step NR NR Oscillated in an ultrasonic bath for 12 h Several days [2 ] SiO2 Deionized water Two-step 0.45, 1.85, and 4 12 Ultrasonic vibration NR [3 ] SiO2 EG, water, EG/water solutions, and TO/water solution Two-Step NR 10 nm with 600 m2 ·g−1 specific surface area Ultrasonic disrupter technique NR [4 ] SiC Water Two-step 9 NR Sonicated for 15 minutes and pH of solution = 9.5 NR (not reported) [5 –7 ] TiO2 EG/water Two-step 0.5–1.5 50 Ultrasonic bath of 2 hours NR [8 ] TiO2 Water Two-step 1, 1.5, and 2.0 6 Mixture sonicated in magnetic stirrer followed by ultrasonic vibration for 2 hours NR [9 ] TiO2 & C-TiO2 EG Two-step 0.04 and 0.08 NR Sonicated at a frequency of 42 kHz NR [10 ] TiO2 & C-TiO2 water Two-step 0.04 and 0.08 NR Sonicated at frequency of 42 kHz NR [10 ] TiO2 Distilled water Two-step NR NR Ultrasonic cleaner used for 30 min NR [11 ] TiO2 Distilled water Two-step 0.01 NR Ultrasonication for 30 min NR [12 ] TiO2 Distilled water Two-step NR NR Ultrasonic vibration (400 W and 24 kHz) for 3–5 hours Several days [13 ] Al2 O3 Wide range NR NR 28 Mechanical blending, coating particles with polymers, and filtration method NR [14 ] Al2 O3 Water Two-step NR 60.4 Ultrasonic disrupter + homogenization by magnetic force agitation NR [15 ] Al2 O3 Water and EG in polyethylene container Two-step NR 38.4 Mixture shaken thoroughly NR [16 ] Al2 O3 EG Two-step NR NR Ultrasonic mixing for several minutes Duration of experiment [17 ] Al2 O3 Water Two-step Wt.% 45 and 150 Ultrasonication + pH kept away from the isoelectric point (IEP) = zero zeta potential Several weeks [18 ] Al2 O3 Water Two-step NR NR Ultrasonic pulses of 100 W and 36 Several weeks [19 , 20 ] Al2 O3 Water Two-step 20 40.2 Mixture diluted by 1% nitric acid + sonication continuously for 4 h at 60 Hz and 130 W One week [21 ] Al2 O3 Water Two-step NR NR Ultrasonic pulses of 100 W and 36 ± 3 kHz for 6 h. pH = 4.8, and zeta potential = 45 mV. Several weeks [22 ] Al2 O3 Water One-step 0.5, 1, & 3 NR Homogenizer at 8000 rpm for 30 min + an electromagnetic agitator at 600 rpm More than 2 weeks [23 ] ZnO Water Two-step NR 150–80 Acetyl acetone + sonication for 10 minutes Over 9 months to 1 year [20 ] ZnO EG Two-step NR NR Continuous stirring & sonicating (40 kHz and 150 W) for 3 hours NR [24 ] ZnO Water Two-step NR 210 Mixture stirred for 30 min at 25°C + sonication using single piezoactuated bath, a solenoid-actuated bath, and a static bath with an immersed horn NR [22 ] ZnO EG/H2 O Two-step 0.1, 0.5, and 1 NR Stabilize mixture by NR [25 ] ZnO Water Two-step NR NR Ultrasonication for 3 h + sodium hexametaphosphate (surfactant: NP ratio = 1 : 5) + high shear homogenization for 20 min at 7000 rpm, followed by ultrasonication for 180 min (750 W and 20 kHz) NR [26 ] ZnO PEG Two-step NR NR Sonication At least 140 min [27 ] ZnO EG Two-step 0.005 and 0.0375 <50 Intense ultrasonication at 200 W up to 100 h + no surfactant NR [28 ] CuO Water One-step NR NR Pulsed laser ablation in liquids using a single-pulsed laser beam for 8 h Better than two-step [29 ] CuO Deionized water Two-step NR NR Continuous sonication for 6 h NR [29 ] CuO Water Two-step NR NR Ultrasonication for 6 h + surfactant Tiron (CuO : Tiron = 2.5 : 1). Zeta potential = 30 mV ensured NR [30 ] CuO Distilled water Two-step 0.05 vol.% NR Sodium dodecyl benzene sulphonate (SDBS) of 10 wt.% of nanoparticles (reason: to prevent immediate settlement as CuO NPs have high density (6310 kg·m−3 ) compared to water (995 kg·m−3 )) + sonication for 60 min Best with SDBS [31 ] CuO Oleic acid Two-step 1, 1.5, & 2 NR Ultrasonicated at a frequency of 40 kHz NR [32 ] CuO EG + water Two-step NR <40 Polyvinylpyrrolidone (PVP) with weight ratio of 0.25 : 1 (PVP : CuO) + mixture stirred and agitated thoroughly for 30 min NR [33 ] CuO Water Two-step NR NR Ultrasonic bath (100 W) for 4 hours 25 days [34 ] CuO Distilled water Two-step NR NR Vibrated for 10 h in an ultrasonic mixer 5 hours [35 ] Fe3 O4 Water + EG (50% : 50%) Two-step NR NR Sonicated for two hours with vigorous agitation for 30 minutes More than 8 hours [36 ] Fe3 O4 Water Two-step NR NR Oleic acid NR [37 ] Fe3 O4 Kerosene Two-step 1 vol.% NR Oleic acid NR [38 ] α -Fe2 O3 Glycerol Two-step NR NR Ultrasonication at 700 W for 30 min NR [39 ] Fe3 O4 Water Two-step NR NR Sonication for 1 hour 12 hours [40 ] Fe3 O4 Water Two-step NR NR Sonication for 2 hours + pH = 3 (use sulfuric acid (H2 SO4 )) NR [41 ] Fe2 O3 Water Two-step 0.02 vol. 40 PH = 11.1 + PEG as surfactant + magnetic stirring for 1 hour 7 days [42 ] Fe2 O3 MAAS (30 mM KOH and 10 mM LiOH in deionized water) Two-step NR 40–150 (Ultrasonic bath, 37 kHz) for 4–6 h + agitation for at least 1 hour with sonication NR [43 ] α -Fe2 O3 Water Two-step 0.25, 0.5, 1, 2, 3, & 4 20–40 Sonication + tetramethylammonium hydroxide NR [44 ] AIN Polypropylene glycol Two-step NR 169 Stirred for 40 min at 3000 rpm 30 hours [45 ] AlN EG Two-step NR 165 Sonication for 3 h NR [46 ] AlN Transformer oil (TO) Two-step NR NR Stirring and ultrasonic vibration without the addition of any surfactant NR [47 ] AlN Ethanol Two-step NR 20 Castor oil + stirring at high speed + ultrasonic homogenizer for 10 min More than two weeks [48 ] Cu Transformer oil NR 22 NR Oleic acid + suspension vibrated for 10 h One week [49 ] Cu Deionized water NR 9 NR Laureate salts + ultrasonic vibration 30 hours [49 ] Cu NR Two-step NR NR Sodium dodecyl sulfate, cetyltrimethylammonium bromide, and sorbitan monooleate 24 hours [50 ] Cu Water Two-step NR NR 9.0% anionic surfactant in an ultrasonic bath for about 10 hours NR [51 ] Cu NR Two-step NR NR Ultrasonic bath for 1.5 hours 4 hours [52 ] Cu Distilled water Two-step NR NR Intense ultrasonication for 10 h at 200 W + magnetic stirrer for another 10 h 15 days [53 ] Cu Water One-step 0.1–0.3 30–50 NR More than 2 weeks (for 0.1%) [54 ] Ag Diethylene glycol Two-step NR NR Continuous stirring & agitation for 5 min by an ultrasonic agitator NR [55 ] Ag nanorods NR Two-step NR NR CTAB surfactant micelles Maximum one week [56 ] Ag NR Two-step NR NR Ultrasonic bath for 3 h 48 hours [57 ] Ag Deionized water Two-step NR NR Ultrasonic bath for about 15 min NR [58 ] Au Distilled water Two-step NR NR Solution boiled for 10 min at 80°C NR [59 ] Au Water (laser ablation) One-step NR NR Stirred magnetically NR [60 ] MWCNT NR (first treated with hydrophilic functional groups) Two-step NR NR NR Several months [61 ] MWCNT NR (not treated) Two-step NR NR With or without oleylamine 5 minutes [61 ] CNTs Gum Arabic + deionized water Two-step NR NR Ultrasonication + magnetic stirring for 5 minutes Over 1 month [62 ] CNTs Water Two-step NR NR 0.2 wt.% chitosan 2 months [63 ] CNTs Glycol Two-step NR NR Ultrasonic vibration (Gum Arabic, Tween 80, and CTAB) More than two months [64 ] CNTs Deionized water Two-step NR NR Hexadecyl-trimethyl-ammonium bromide (CTAB) 120 minutes [65 ] Alumina CNFs EG Two-step 5.5 vol.% NR Sonication for 1 hour NR [66 ] NCFs Deionized water Two-step NR NR Stirring + ultrasonication for 1 hour at 25°C NR [67 ] TiO2 nanorods Deionized water Two-step 0.05 10 Ultrasonic NR [68 ] ZnO nanorods Deionized water Two-step 0.01–0.1 140 Ammonia citrate at a ZnO/ammonium citrate ratio of 1 : 1 (sonication for about 15 min.) NR [69 ] CuO nanorods Heat transfer oil Two-step 0.8% 40–60 nm in diameter and 100–120 nm in length NR NR [70 ]
