Ramesh and Prabhu Nanoscale Research Letters 2011, 6:334 http://www.nanoscalereslett.com/content/6/1/334 Page 4 of 15 Table 1 Enhancement of thermal conductivity of water on addition of nanoparticles reported in the literature [13.14.17-42] Particle material Particle size (nm) Concentration Thermal conductivity Remarks Reference (vol.%) ratio (Keff/Kf) Cu 100 2.50-7.50 1.24-1.78 Laurate salt Surfactant [18] 100-200 0.05 1.116 Spherical and square [19] Not available 0.05 1.036 - 130-200 0.05 1.085 Spherical and square 75-100 0.1 1.238 Spherical and square 50-100 0.1 1.238 Spherical and square 100-300 0.1 1.110 Spherical, square, and needle 130-300 0.2 1.097 Spherical 200 × 500 0.2 1.132 Needle 250 0.2 1.036 Spherical, square, and needle Ag 60-70 0.001 1.30 30°C [20] 1.04 40°C 8-15 0.10-0.39 1.03-1.11 - [21] Au 10-20 0.00013 1.03 30°C (citerate reduced) [20] 1.05 40°C (citerate reduced) 0.00026 1.05 30°C (citerate reduced) 1.08 60°C (citerate reduced) Fe 10 0.2-0.55 1.14-1.18 - [22] Al2Cu 30 1.0-2.0 1.48-1.98 - [23] 65 1.4-1.78 - 104 1.35-1.60 - Ag2Al 30 1.0-2.0 1.5-2.1 - [23] 80 1.4-1.9 - 120 1.3-1.75 - CuO 36 5 1.6 - [13] 23.6 1.00-3.41 1.03-1.12 - [24] 23 4.50-9.70 1.18-1.36 - [17] 28.6 1.00-4.00 1.07-1.14 21°C [25] 1.22-1.26 36°C 1.29-1.36 51°C - 1.00 1.05 - [26] 25 0.03-0.30 1.04-1.12 pH = 3 [27] 1.02-1.07 pH = 6 29 2.00-6.00 1.35-1.36 28.9°C [28] 1.35-1.50 31.3°C 1.38-1.51 33.4°C 29 0-16 1.00-1.24 - [29] Al2O3 13 1.30-4.30 1.109-1.324 31.85°C [30] 1.100-1.296 46.85°C 1.092-1.262 66.85°C 38.4 1.00-4.30 1.03-1.10 - [24] 28 3.00-5.00 1.12-1.16 - [17] 60.4 1.80-5.00 1.07-1.21 - [31] 60.4 5.00 1.23 - [32] 38.4 1.00-4.00 1.02-1.09 21°C [25] 1.07-1.16 36°C 1.10-1.24 51°C 27-56 1.6 1.10 Sodium dodeculbenzene sulfonate [33] 11 1.00 1.09 21°C [34] 1.15 71°C