Stability, Thermophysical, Optical and Photothermal Properties of ZnO Nanofluids with Added Anionic/Cationic Mixed Surfactants

Abstract

Abstract Metal oxide nanofluid is a new type of heat transfer medium with good thermal performance, which can be used to improve the heat collection and photothermal conversion performance of the collector. The development of new nanofluids with excellent stability, thermophysical and photothermal properties is very important for solar thermal utilization. In this paper, the ZnO nanofluids with SDS/CTAB mixed surfactants were prepared by two-step method. Their stability, thermophysical, optical and photothermal properties were studied based on experimental data. Then, the optimum concentration and preparation conditions of the proposed ZnO nanofluid adding SDS/CTAB with good photothermal performance were obtained. The results showed that the ZnO nanofluid adding SDS/CTAB mixed surfactants has good dispersion stability and thermal physical properties with thermal conductivity up to 0.772 W/(m·K). Moreover, it has the lowest transmittance of 0.10% and the highest extinction coefficient of 7.25 cm-1. Moreover, the addition of SDS/CTAB mixed surfactants makes ZnO nanofluids show better photothermal conversion efficiency, up to 87%. Therefore, ZnO nanofluids with SDS/CTAB added have great potential as working fluids for DASC.