In nanofluid preparation, surfactants such as gum Arabic, sodium dodecylbenzenesulfonate, and polyvinylpyrrolidone are often added to minimize the nanoparticles sedimentation problems and eventually improve nanofluids stability. However, the inclusion of surfactant will affect the thermal conductivity of nanofluids. Proper amount of surfactant is required not only to improve nanofluids stability but also to optimize its thermal conductivity enhancement. Thus, the present study investigated the effect of gum Arabic, sodium dodecylbenzenesulfonate and polyvinylpyrrolidone with two different surfactant to nanoparticles ratio (1:1 and 2:1) on thermal conductivity of titanium dioxide water based nanofluids. The nanofluid samples were prepared via two-step method while KD2-Pro thermal analyser was used to measure the thermal conductivity. Study concluded that the thermal conductivity of non-surfactant titanium dioxide based nanofluids is higher than surfactant based titanium dioxide nanofluids. This study concludes that in comparison with types of surfactant, nanofluids (1:1 ratio) at 0.8 volume percentage of titanium dioxide added with sodium dodecylbenzenesulfonate exhibit highest thermal conductivity value followed by gum Arabic and polyvinylpyrrolidone
