Kim Nanoscale Research Letters 2011, 6:415 http://www.nanoscalereslett.com/content/6/1/415 confirmed for SiO2 particles in water by Vassallo et al. [6]. However, the causes of CHF increases in nanofluids could not be explained using traditional CHF correla- tions. Since the publication of these pioneering works, extensive experimental studies have been conducted in this area over the past decade. Studies of CHF increase in nanofluids are summarized in Tables 1 and 2 accord- ing to pool and flow conditions, respectively. In this section, characteristics of CHF enhancement in nanofluids that have been identified from an exhaustive review of published studies over the past decade will be summarized in terms of the effects of primary [57] [21] [19] [23] [35] [74] [36] [69] [28,75,76] [27] [63] Table 1 Summary of studies on CHF of nanofluids in pool boiling Reference Nanofluids [5] Al2O3 in water [6] SiO2 (15, 50, 3,000 nm) in water [72] Al2O3 (38 nm) in water [45] TiO2 (27, 85 nm) in water [22] Al2O3 (70-260 nm), ZnO in water; Al2O3 in ethylene glycol [47] Al2O3 (47 nm) in water [73] Gold (3 nm) in water, 2.3 kPa [32,33] SiO2 (10-20 nm) in ionic solution of water [18,53,59,60] TiO2 (23 nm) Al2O3 (47 nm) in water SiO2 (10 nm) [46,55] Al2O3 (110-210 nm) ZrO2 (110-250 nm) in water SiO2 (20-40 nm) [20] CuO (30 nm) in water Concentration Test heater 0.001-0.025 g/l Cu plate (10 × 10 mm2) 0.5 vol.% 0.037 g/l 0.01-3 vol.% - 0.5-4 vol.% - 0.5 vol.% 10-5-10-1 vol.% NiCr wire (j = 1 mm) Ti layer on glass Cu plate Cu plate SS plate (4 × 100 mm2) Cu disk (1 cm2) NiCr wire (j = 0.32 mm) NiCr wire (j = 0.2 mm) Ti wire (j = 0.25 mm) 10-3-10-1 vol.% SS wire (j = 0.381 mm) 0.1-2.0 wt.% Cu plate (40 × 40 mm2); with grooves Al2O3 (45 nm) in water and ethanol 0.001-10 g/l CuO (59 nm) and SiO2 (35 nm) in water and alcohol (C2H4OH) with 0.2-2 wt.% SDBS surfactant Al2O3 (22.6, 46 nm) in water 0.0006-0.01 g/l BiO2 (38 nm) Al2O3 (<25 nm) in water 10-4-10-1 g/l Ag (3, 10, 80, 150, 250 nm) Single-walled CNT in water with hydrochloric acid 2 wt.% 10-4-10-2, 0.05 Multi-walled CNT in water with PVP polymer vol.% Glass, Au, and Cu surfaces Cu disk (j = 20 mm) NiCr wire (j = 0.64 mm) Cu disk (j = 10 and 15 mm) NiCr wire (j = 0.32 mm) Cu plate (9.5 × 9.5 mm2) Ti wire (j = 0.25 mm) Cu (10-20 nm) in water w/ SDS surfactant w/o SDS surfactant TiO2 (45 nm) and Al2O3 (47 nm) in water Al2O3 (139 nm), CuO (143 nm), Diamond (86 nm) in water CNT in water with nitric acid for pH 6.5; Graphene in water Graphene-oxide in water Al2O3 in water 0.25, 0.5, 1.0 wt. Plate (30 × 30 mm2) % 0.01 vol.% 0.001-1 g/l 0.5-4 wt.% Cu and Ni disks (j = 20 mm) Cu plate (10 × 10 mm2) Cu plate (40 × 40 mm2) 0.001 vol.% NiCr wire Page 2 of 18 CHF enhancement 200%, (19.9 kPa) 60% 70% 50% 200% 50% 180% 220-320% 100% 80% 170% 50% 75% 80% 50%, (100 kPa) 140%, (31.2 kPa) 220% (7.4 kPa) 40% 30% 50% 33% 70% 35% 300% 200% (19.9 kPa) 140% (19.9 kPa) 50% -30% 40% 80% 60% (100 kPa) 140% (31.2 kPa) 200% (7.4 kPa) 84% 179% 152%