Thermal Conductivity Enhancement of Binary Nanoemulsion(O/S) for Absorption Application

Binary nanoemulsions, oil-droplet suspensions in binary solution (H₂O/LiBr), are developed to enhance the heat and mass transfer performance of absorption refrigeration cycles. This paper studies the formation and stability of n-decane in H₂O/LiBr nanoemulsions produced by using polyoxyethylene lauryl ether and polyoxyethylene sorbitan monolaurate as surfactant. To stabilize the nanoemulsions in a strong electrolyte, polymeric stabilizer (gum Arabic) is used as a steric stabilizer. The droplet size and the thermal conductivity of binary nanoemulsions are measured by the dynamic light scattering method and the transient hot-wire method, respectively. It is found that the effective thermal conductivity of binary nanoemulsions (1.0 vol % of n-decane in 30 wt % H₂O/LiBr) enhances up to 3.59% with the average droplet size of 44.3 nm. The stability has more significant effect on the thermal conductivity enhancement than the initial drop size.